Patent Publication Number: US-4839097-A

Title: Voltage-dependent non-linear resistance ceramic composition

Description:
This is a continuation of application Ser. No. 708,079, filed Feb. 26, 1985 which was abandoned upon the filing hereof. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a voltage dependent non-linear resistance ceramic composition for use in surge absorbing and noise elimination in various electric apparatuses and electronic apparatuses. 
     BACKGROUND ART 
     Heretofore, in various electric apparatuses and electronic apparatuses, in order to absorb extraordinary high voltage, elimination of noise, elimination of arc, and the like, SiC varistors or varistors of ZnO system having a voltage-dependent non-linear resistance characteristics are used. Voltage-current characteristic of such varistors can be approximately represented by the following equation: 
     
         I=(V/C).sup.α, 
    
     wherein I is current, V is voltage, C is a constant proper for the varistor, and α is a voltage non-linearity exponent. 
     The α of the SiC varistor is about 2-7, and for the ZnO system varistor there is ones that reaching 50. Though such varistors has superior characteristic for absorbing relatively high voltage called surge, for voltages lower than varistor voltage (for instance, absorption of noise) almost no effect is represented since its dielectric constant is low and its inherent capacitance is small, and their dielectric loss tan δ are so large as 5-10%. 
     On the other hand, for elimination of low voltage noise, static electricity, or the like, by appropriately selecting composition and firing condition, semiconductor ceramic capacitors having apparent dielectric constant of about 5×10 4  -6×10 4  and tan δ of about 1% are utilized. 
     However, these semiconductor ceramic capacitor is liable to be destroyed or become to be non-functional as capacitors when extraordinary high voltage such as surge is impressed thereon or a current above a certain limit is impressed on the element. For such reason, in the electric apparatuses or electronic apparatuses, for the purpose of both the absorbing of high voltage surge and the elimination of low volage noise, the varistors are used being combined with capacitors and other component (for instance, coil), and for instance, a noise filter has such configuration. 
     FIG. 1 shows general noise filter circuit, FIG. 2 shows a conventional noise filter circuit constituted by combining a varistor, capacitors and a coil, and 1 is the coil, 2 and the capacitors and 3 is the varistor. 
     When a noise input A shown in FIG. 5 is impressed on these circuits, output characteristics from general noise filter circuit of FIG. 1 is such as C of FIG. 5, and noise is not eliminated sufficiently. Output characteristic from the conventional noise filter circuit including a varistor shown in FIG. 2 is such as B of FIG. 5, and though noise is eliminated, such configuration has a shortcoming that it has large number of components in the inside of the apparatus and besides is contrary to tendency of miniaturization of the apparatus. 
     Accordingly, an electronic component, which absorbs extraordinary high voltage, can eliminate low voltage, such as noise and has small number of components, and capable of miniaturization, is demanded. 
     DISCLOSURE OF THE INVENTION 
     Accordingly, the present invention intends to provide a voltage-dependent non-linear resistance ceramic composition comprising 90.800-99.996 mol % of SrTiO 3  and as metal oxides for semiconductorization acceleration 0.001-0.200 mol % of Nb 2  O 5  and 0.001-5.000 mol % of Ta 2  O 5 , and is characterized by containing 0.001-2.000 mol % in the form of oxide of at least one kind of element selected from the group consisting of Ga, Pt, Tl, Si, Ti, Cs, Au, S, Be, Al, Ca, Cd, In, Ba, Eu, Gd, Tb, Tm, Lu, Th, Ir, Os, Hf, Ru, Mg, Zr, Sn, Sb and. 
    
    
     BRIEF EXPLANATION OF THE DRAWING 
     FIG. 1 is a circuit diagram of a general noise filter, FIG. 2 is a circuit diagram of a noise filter using the conventional varistors and the capacitors, FIG. 3 is a sectional view of an element using voltage dependent non-linear resistance ceramic composition in accordance with the present invention, FIG. 4 is a circuit diagram of a noise filter using the voltage dependent non-linear resistance ceramic composition in accordance with the present invention, FIG. 5 is a characteristic chart showing situation of input noise and output in accordance with circuit of noise filters of the present invention and the prior art. 
    
    
     THE BEST MODE FOR EMBODYING THE INVENTION 
     As a result of accumulating various experiments the inventors propose a voltage dependent non-linear resistance ceramic composition in a different system from the conventional composition by making strontium-titanate (SrTiO 3 ) as host material, and adding either one of Nb 2  O 5  and Ta 2  O 5  as semi-conductorization accelerating agent, and by further adding MnO 2  and appropriate amount of other additives; hereafter the present invention is described with respect to embodiments. 
     EXAMPLE 1 
     After measuring SrTiO 3 , Nb 2  O 5 , Ta 2  O 5 , MnO 2  and Tl 2  O to become composition ratio as shown in the below-mentioned Table 1, they are blended for 6 hours in wet method in a ball-mill or the like, and after drying is calcinated for 1-5 hours at 1000°-1250° C. in the air. Thereafter, after grinding for 4 hours in wet method in ball mill or the like and subsequently drying, and after granulating by adding 8 wt % of organic binder (for instance, polyvinylalcohol), press-forming to the size of 8.0 (mm) φ×1.0 (mm) t with a pressing force of 1.0 t/cm 2 . The granulated body is fired in a reducing atmosphere (for instance, N 2  :H 2  =10:1) at 1300°-1450° C. for 1-6 hours. The fired body thus obtained has a specific resistance of 0.1-0.8 Ω.cm, and average granular size is 20-50 μm. Then, the dired body is further fired in air at 1000°-1300° C. for 0.5-5 hours, to obtain fired body 4 of FIG. 3. Furthermore, the both faces of the fired body 4 are ground with abrasive such as SiC and electrodes 5, 6 are formed by using a conductive metal such as Ag. Diameter of the above-mentioned electrodes 5, 6 are selected to be 5.0 (mm) φ. 
     Characteristics of the element thus obtained are shown in Table 1. 
     
                                           TABLE 1                                 
__________________________________________________________________________
Sample                                                                    
    Composition ratio (mol %)                                             
                        Characteristic value                              
No. SrTiO.sub.3                                                           
        Nb.sub.2 O.sub.5                                                  
            Ta.sub.2 O.sub.5                                              
                MnO.sub.2                                                 
                    Tl.sub.2 O                                            
                        V.sub.1 mA/mm (V)                                 
                                α                                   
                                   ε                              
                                         tan δ (%)                  
__________________________________________________________________________
 1* 99.795                                                                
        0.100                                                             
            0   0.100                                                     
                    0.005                                                 
                        1240    3.5                                       
                                   1 × 10.sup.3                     
                                         5.4                              
 2* 99.300                                                                
        0.100                                                             
            0   0.500                                                     
                    0.100                                                 
                        1460    5.7                                       
                                   1 × 10.sup.3                     
                                         10.9                             
 3* 99.899                                                                
        0.100                                                             
            0.001                                                         
                0   0    90     3.0                                       
                                   1 × 10.sup.3                     
                                         4.2                              
 4* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0   0.001                                                 
                        110     4.2                                       
                                   1 × 10.sup.3                     
                                         3.6                              
 5* 99.799                                                                
        0.100                                                             
            0.001                                                         
                0   0.100                                                 
                        117     4.9                                       
                                   2 × 10.sup.3                     
                                         3.0                              
 6* 97.899                                                                
        0.100                                                             
            0.001                                                         
                0   2.000                                                 
                        135     5.6                                       
                                   2 × 10.sup.3                     
                                         3.0                              
 7* 96.899                                                                
        0.100                                                             
            0.001                                                         
                0   3.000                                                 
                        175     5.5                                       
                                   2 × 10.sup.3                     
                                         4.6                              
 8* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0   100     5.7                                       
                                   4 × 10.sup.3                     
                                         4.1                              
9   99.897                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.001                                                 
                        120     8.6                                       
                                   8 × 10.sup.3                     
                                         3.5                              
10  99.798                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.100                                                 
                        128     9.7                                       
                                   9 × 10.sup.3                     
                                         3.0                              
11  97.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    2.000                                                 
                        142     9.7                                       
                                   9 × 10.sup.3                     
                                         2.9                              
12* 96.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    3.000                                                 
                        164     9.5                                       
                                   5 × 10.sup.3                     
                                         3.9                              
13* 98.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0   150     8.2                                       
                                   4 × 10.sup.3                     
                                         4.5                              
14  98.898                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.001                                                 
                        157     8.7                                       
                                   8 × 10.sup.3                     
                                         4.0                              
15  98.799                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.100                                                 
                        167     9.6                                       
                                   9 × 10.sup.3                     
                                         3.4                              
16  96.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    2.000                                                 
                        173     9.8                                       
                                   1.0 × 10.sup.4                   
                                         3.0                              
17* 95.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    3.000                                                 
                        182     9.2                                       
                                   6 × 10.sup.3                     
                                         7.1                              
18* 97.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0   190     8.8                                       
                                   5 × 10.sup.3                     
                                         10.1                             
19  97.898                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.001                                                 
                        198     8.0                                       
                                   9 × 10.sup.3                     
                                         10.1                             
20  97.799                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.100                                                 
                        202     8.7                                       
                                   9 × 10.sup.3                     
                                         9.3                              
21  95.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    2.000                                                 
                        204     8.7                                       
                                   1.0 × 10.sup.4                   
                                         8.9                              
22* 94.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    3.000                                                 
                        255     7.9                                       
                                   5 × 10.sup.3                     
                                         7.8                              
23* 98.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0    90     8.0                                       
                                   4 × 10.sup.3                     
                                         4.0                              
24  98.898                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.001                                                 
                        100     9.2                                       
                                   8 × 10.sup.3                     
                                         2.7                              
25  98.799                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.100                                                 
                        111     11.3                                      
                                   9 × 10.sup.3                     
                                         2.3                              
26  96.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    2.000                                                 
                        127     11.6                                      
                                   1.1 × 10.sup.4                   
                                         2.3                              
27* 95.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    3.000                                                 
                        156     9.1                                       
                                   6 × 10.sup.3                     
                                         6.3                              
28* 97.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0   130     8.2                                       
                                   5 × 10.sup.3                     
                                         4.2                              
29  97.899                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.001                                                 
                        147     9.2                                       
                                   8 × 10.sup.3                     
                                         2.9                              
30  97.800                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.100                                                 
                        156     12.0                                      
                                   9 × 10.sup.3                     
                                         2.5                              
31  95.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    2.000                                                 
                        162     11.5                                      
                                   1.1 × 10.sup.4                   
                                         2.3                              
32* 94.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    3.000                                                 
                        175     9.0                                       
                                   7 × 10.sup.3                     
                                         5.4                              
33* 96.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0   180     8.0                                       
                                   6 × 10.sup.3                     
                                         10.0                             
34  96.899                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.001                                                 
                        198     8.0                                       
                                   7 × 10.sup.3                     
                                         9.5                              
35  96.800                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.100                                                 
                        213     8.1                                       
                                   7 × 10.sup.3                     
                                         9.0                              
36  94.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    2.000                                                 
                        233     8.5                                       
                                   7 ×  10.sup.3                    
                                         8.9                              
37* 93.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    3.000                                                 
                        260     7.9                                       
                                   8 × 10.sup.3                     
                                         8.8                              
38* 94.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0    75     7.2                                       
                                   7 × 10.sup.3                     
                                         3.8                              
39  94.898                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.001                                                 
                         85     7.7                                       
                                   7 × 10.sup.3                     
                                         3.0                              
40  94.799                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.100                                                 
                         96     9.3                                       
                                   8 × 10.sup.3                     
                                         2.5                              
41  92.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    2.000                                                 
                        112     9.8                                       
                                   9 × 10.sup.3                     
                                         2.4                              
42* 91.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    3.000                                                 
                        127     9.0                                       
                                   5 × 10.sup.3                     
                                         3.5                              
43* 93.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0    82     7.6                                       
                                   7 × 10.sup.3                     
                                         3.9                              
44  93.899                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.001                                                 
                         94     8.4                                       
                                   9 × 10.sup.3                     
                                         2.6                              
45  93.800                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.100                                                 
                        112     10.2                                      
                                   1 × 10.sup.4                     
                                         2.5                              
46  91.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    2.000                                                 
                        115     10.1                                      
                                   1.1 × 10.sup.4                   
                                         2.5                              
47* 90.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    3.000                                                 
                        139     9.5                                       
                                   6 × 10.sup.3                     
                                         4.3                              
48* 92.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0    95     8.4                                       
                                   7 × 10.sup.3                     
                                         9.4                              
49* 92.899                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.001                                                 
                        121     9.1                                       
                                   7 × 10.sup.3                     
                                         9.3                              
50* 92.800                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.100                                                 
                        131     10.2                                      
                                   8 × 10.sup.3                     
                                         9.0                              
51* 90.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    2.000                                                 
                        138     10.2                                      
                                   8 × 10.sup.3                     
                                         8.6                              
52* 89.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    3.000                                                 
                        195     8.5                                       
                                   4 × 10.sup.3                     
                                         9.2                              
53* 92.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0    40     4.0                                       
                                   6 × 10.sup.3                     
                                         6.2                              
54* 92.898                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.001                                                 
                         60     4.3                                       
                                   6 × 10.sup.3                     
                                         6.1                              
55* 92.799                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.100                                                 
                         63     4.3                                       
                                   6 × 10.sup.3                     
                                         5.9                              
56* 90.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    2.000                                                 
                         69     4.5                                       
                                   6 × 10.sup.3                     
                                         5.9                              
57* 89.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    3.000                                                 
                        102     4.7                                       
                                   5 × 10.sup.3                     
                                         7.8                              
58* 91.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0    49     4.4                                       
                                   6 × 10.sup.3                     
                                         10.2                             
59* 91.899                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.001                                                 
                         75     4.8                                       
                                   6 × 10.sup.3                     
                                         10.1                             
60* 91.800                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.100                                                 
                         81     5.2                                       
                                   6 × 10.sup.3                     
                                         10.0                             
61* 89.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    2.000                                                 
                         93     5.8                                       
                                   5 × 10.sup.3                     
                                         9.8                              
62* 88.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    3.000                                                 
                        124     5.0                                       
                                   4 × 10.sup.3                     
                                         9.9                              
63* 95.800                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    0.100                                                 
                        211     4.2                                       
                                   5 × 10.sup.3                     
                                         23.1                             
64* 92.900                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    3.000                                                 
                        244     5.3                                       
                                   4 × 10.sup.3                     
                                         21.0                             
__________________________________________________________________________
 *Comparison sample                                                       
 
    
     Herein, evaluation of characteristics of the elements as varistor can be made by α and C in a voltage-current characteristic equation: 
     
         I=(V/C).sup.α 
    
     (wherein I is current, V is voltage, C is a constant proper to the varistor and α is a non-linearity exponent). Since accurate measurement of C is difficult, in the present invention, characteristic assessment as varistor is made by the value of varistor voltage for unit thickness when 1 mA of varistor current is flowed (hereinafter is called as V 1  mA/mm.) and by a value of 
     
         α=1/log (V.sub.10 mA/V.sub.1 mA) 
    
     (wherein V 10  mA is a varistor voltage when a varistor current of 10 mA is flowed and V 1  mA is a varistor voltage when varistor current of 1 mA is flowed). 
     And characteristic assessment as the capacitors are made by a dielectric constant ε and dielectric loss tan δ at a measurement frequency of 1 KHz. The above-mentioned data are those for firing temperature and time in the reducing atmosphere was 1400° C. and 2 hours, respectively and firing temperature and time in air was 1200° C. and 3 hours, respectively. 
     EXAMPLE 2 
     SrTiO 3 , Nb 2  O 5 , Ta 2  O 5 , MnO 2  and Y 2  O 5  are made in a composition ratio shown in the below-mentioned Table 2, and mixing, forming and firings are carried out in a similar operation as the above-mentioned EXAMPLE 1, and measurements are made in the similar conditions and results are shown in Table 2. 
     
                                           TABLE 2                                 
__________________________________________________________________________
Sample                                                                    
    Composition ratio (mol %)                                             
                        Characteristic value                              
No. SrTiO.sub.3                                                           
        Nb.sub.2 O.sub.5                                                  
            Ta.sub.2 O.sub.5                                              
                MnO.sub.2                                                 
                    Y.sub.2 O.sub.3                                       
                        V.sub.1 mA/mm (V)                                 
                                α                                   
                                   ε                              
                                         tan δ (%)                  
__________________________________________________________________________
 1* 99.795                                                                
        0.100                                                             
            0   0.100                                                     
                    0.005                                                 
                        1350    3.5                                       
                                   1 × 10.sup.3                     
                                         5.3                              
 2* 99.300                                                                
        0.100                                                             
            0   0.500                                                     
                    0.100                                                 
                        1530    5.2                                       
                                   3 × 10.sup.3                     
                                         9.2                              
 3* 99.899                                                                
        0.100                                                             
            0.001                                                         
                0   0    90     3.0                                       
                                   1 × 10.sup.3                     
                                         4.2                              
 4* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0   0.001                                                 
                        102     4.0                                       
                                   1 × 10.sup.3                     
                                         2.7                              
 5* 99.799                                                                
        0.100                                                             
            0.001                                                         
                0   0.100                                                 
                        110     4.7                                       
                                   2 × 10.sup.3                     
                                         2.0                              
 6* 97.899                                                                
        0.100                                                             
            0.001                                                         
                0   2.000                                                 
                        130     5.7                                       
                                   3 × 10.sup.3                     
                                         2.1                              
 7* 96.899                                                                
        0.100                                                             
            0.001                                                         
                0   3.000                                                 
                        162     5.8                                       
                                   2 × 10.sup.3                     
                                         2.2                              
 8* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0   100     5.7                                       
                                   4 × 10.sup.3                     
                                         4.1                              
9   99.897                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.001                                                 
                        105     8.4                                       
                                   8 × 10.sup. 3                    
                                         2.6                              
10  99.798                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.100                                                 
                        114     9.5                                       
                                   9 × 10.sup.3                     
                                         2.0                              
11  97.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    2.000                                                 
                        138     9.7                                       
                                   1 × 10.sup.4                     
                                         2.0                              
12* 96.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    3.000                                                 
                        152     10.1                                      
                                   6 × 10.sup.3                     
                                         2.8                              
13* 98.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0   150     8.2                                       
                                   4 × 10.sup.3                     
                                         4.5                              
14  98.898                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.001                                                 
                        155     8.5                                       
                                   9 × 10.sup.3                     
                                         3.1                              
15  98.799                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.100                                                 
                        164     9.4                                       
                                   1 × 10.sup.4                     
                                         2.6                              
16  96.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    2.000                                                 
                        173     10.0                                      
                                   1.1 × 10.sup.4                   
                                         2.2                              
17* 95.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    3.000                                                 
                        178     10.4                                      
                                   6 × 10.sup.3                     
                                         2.0                              
18* 97.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0   190     8.8                                       
                                   5 × 10.sup.3                     
                                         10.1                             
19  97.898                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.001                                                 
                        210     8.7                                       
                                   9 × 10.sup.3                     
                                         9.0                              
20  97.799                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.100                                                 
                        218     9.3                                       
                                   1.1 × 10.sup.4                   
                                         8.9                              
21  95.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    2.000                                                 
                        232     10.2                                      
                                   1.1 × 10.sup.4                   
                                         7.9                              
22* 94.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    3.000                                                 
                        260     10.0                                      
                                   8 × 10.sup.3                     
                                         6.8                              
23* 98.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0    90     8.0                                       
                                   4 × 10.sup.3                     
                                         4.0                              
24  98.898                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.001                                                 
                         95     8.9                                       
                                   9 × 10.sup.3                     
                                         2.9                              
25  98.799                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.100                                                 
                        103     11.2                                      
                                   1.0 × 10.sup.4                   
                                         2.0                              
26  96.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    2.000                                                 
                        125     11.8                                      
                                   1.1 × 10.sup.4                   
                                         2.0                              
27* 95.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    3.000                                                 
                        149     10.1                                      
                                   7 × 10.sup.3                     
                                         2.1                              
28* 97.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0   130     8.2                                       
                                   5 × 10.sup.3                     
                                         4.2                              
29  97.899                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.001                                                 
                        140     9.0                                       
                                   9 × 10.sup.3                     
                                         3.0                              
30  97.800                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.100                                                 
                        149     11.8                                      
                                   1.2 × 10.sup.4                   
                                         2.2                              
31  95.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    2.000                                                 
                        152     11.6                                      
                                   1.4 × 10.sup.4                   
                                         2.0                              
32* 94.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    3.000                                                 
                        168     9.5                                       
                                   6 × 10.sup.3                     
                                         2.0                              
33* 96.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0   180     8.0                                       
                                   6 × 10.sup.3                     
                                         10.0                             
34  96.899                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.001                                                 
                        192     8.3                                       
                                   8 × 10.sup.3                     
                                         9.0                              
35  96.800                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.100                                                 
                        209     8.4                                       
                                   1.1 × 10.sup.4                   
                                         8.9                              
36  94.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    2.000                                                 
                        213     8.9                                       
                                   1.4 × 10.sup.4                   
                                         8.8                              
37* 93.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    3.000                                                 
                        255     9.1                                       
                                   5 × 10.sup.3                     
                                         8.3                              
38* 94.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0    75     7.2                                       
                                   7 × 10.sup.3                     
                                         3.8                              
39  94.898                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.001                                                 
                         84     7.4                                       
                                   9 × 10.sup.3                     
                                         2.7                              
40  94.799                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.100                                                 
                         95     9.0                                       
                                   9 × 10.sup.3                     
                                         2.4                              
41  92.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    2.000                                                 
                        112     10.0                                      
                                   1.1 × 10.sup.4                   
                                         2.0                              
42* 91.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    3.000                                                 
                        121     10.2                                      
                                   6 × 10.sup.3                     
                                         2.0                              
43* 93.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0    82     7.6                                       
                                   7 × 10.sup.3                     
                                         3.9                              
44  93.899                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.001                                                 
                         95     8.1                                       
                                   1 × 10.sup.4                     
                                         2.8                              
45  93.800                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.100                                                 
                        102     9.9                                       
                                   1.2 × 10.sup.4                   
                                         2.6                              
46  91.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    2.000                                                 
                        109     10.2                                      
                                   1.1 × 10.sup.4                   
                                         2.3                              
47* 90.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    3.000                                                 
                        123     10.5                                      
                                   5 × 10.sup.3                     
                                         2.2                              
48* 92.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0    95     8.4                                       
                                   7 × 10.sup.3                     
                                         9.4                              
49  92.899                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.001                                                 
                        108     9.0                                       
                                   8 × 10.sup.3                     
                                         9.3                              
50  92.800                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.100                                                 
                        119     10.8                                      
                                   9 × 10.sup.3                     
                                         8.0                              
51  90.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    2.000                                                 
                        124     12.0                                      
                                   1 × 10.sup.4                     
                                         8.0                              
52* 89.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    3.000                                                 
                        148     10.1                                      
                                   7 × 10.sup.3                     
                                         7.2                              
53* 92.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0    40     4.0                                       
                                   6 × 10.sup.3                     
                                         6.2                              
54* 92.898                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.001                                                 
                         53     4.2                                       
                                   7 × 10.sup.3                     
                                         6.1                              
55* 92.799                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.100                                                 
                         56     4.3                                       
                                   8 × 10.sup.3                     
                                         5.8                              
56* 90.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    2.000                                                 
                         64     6.0                                       
                                   8 × 10.sup.3                     
                                         6.0                              
57* 89.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    3.000                                                 
                         71     5.3                                       
                                   7 × 10.sup.3                     
                                         5.9                              
58* 91.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0    49     4.4                                       
                                   6 × 10.sup.3                     
                                         10.2                             
59* 91.988                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.001                                                 
                         60     4.4                                       
                                   8 × 10.sup.3                     
                                         9.2                              
60* 91.800                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.100                                                 
                         64     5.0                                       
                                   8 × 10.sup.3                     
                                         8.9                              
61* 89.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    2.000                                                 
                         84     7.0                                       
                                   7 × 10.sup.3                     
                                         9.0                              
62* 88.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    3.000                                                 
                         92     6.0                                       
                                   7 × 10.sup.3                     
                                         9.1                              
63* 95.800                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    0.100                                                 
                        194     7.2                                       
                                   4 × 10.sup.3                     
                                         19.2                             
64* 92.900                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    3.000                                                 
                        281     6.6                                       
                                   3 × 10.sup.3                     
                                         18.0                             
__________________________________________________________________________
 *Comparison sample                                                       
 
    
     EXAMPLE 3 
     SrTiO 3 , Nb 2  O 5 , Ta 2  O 5 , MnO 2  and BaO are made in a composition ratio shown in the below-mentioned Table 3, and mixing, forming and firings are carried out in a similar operation as the above-mentioned Example 1, and measurements are made in the similar conditions and results are shown in Table 3. 
     
                                           TABLE 3                                 
__________________________________________________________________________
Sample                                                                    
    Composition ratio (mol %)                                             
                        Characteristic value                              
No. SrTiO.sub.3                                                           
        Nb.sub.2 O.sub.5                                                  
            Ta.sub.2 O.sub.5                                              
                MnO.sub.2                                                 
                    BaO V.sub.1 mA/mm (V)                                 
                                α                                   
                                   ε                              
                                         tan δ (%)                  
__________________________________________________________________________
 1* 99.795                                                                
        0.100                                                             
            0   0.100                                                     
                    0.005                                                 
                        1300    3.4                                       
                                   1 × 10.sup.3                     
                                         5.2                              
 2* 99.300                                                                
        0.100                                                             
            0   0.500                                                     
                    0.100                                                 
                        1550    5.0                                       
                                   2 × 10.sup.3                     
                                         8.3                              
 3* 99.899                                                                
        0.100                                                             
            0.001                                                         
                0   0    90     3.0                                       
                                   1 × 10.sup.3                     
                                         4.2                              
 4* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0   0.001                                                 
                         98     4.1                                       
                                   1 × 10.sup.3                     
                                         2.8                              
 5* 99.799                                                                
        0.100                                                             
            0.001                                                         
                0   0.100                                                 
                        105     4.8                                       
                                   3 × 10.sup.3                     
                                         2.1                              
 6* 97.899                                                                
        0.100                                                             
            0.001                                                         
                0   2.000                                                 
                        121     5.6                                       
                                   3 × 10.sup.3                     
                                         2.0                              
 7* 96.899                                                                
        0.100                                                             
            0.001                                                         
                0   3.000                                                 
                        155     5.9                                       
                                   1 × 10.sup.3                     
                                         1.9                              
 8* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0   100     5.7                                       
                                   4 × 10.sup.3                     
                                         4.1                              
9   99.897                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.001                                                 
                        102     8.6                                       
                                   8 × 10.sup.3                     
                                         2.7                              
10  99.798                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.100                                                 
                        111     9.8                                       
                                   8 × 10.sup.3                     
                                         2.0                              
11  97.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    2.000                                                 
                        135     10.5                                      
                                   9 × 10.sup.3                     
                                         2.0                              
12* 96.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    3.000                                                 
                        150     11.2                                      
                                   5 × 10.sup.3                     
                                         2.0                              
13* 98.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0   150     8.2                                       
                                   4 × 10.sup.3                     
                                         4.5                              
14  98.898                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.001                                                 
                        152     8.9                                       
                                   8 × 10.sup.3                     
                                         3.0                              
15  98.799                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.100                                                 
                        160     10.1                                      
                                   9 × 10.sup.3                     
                                         2.6                              
16  96.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    2.000                                                 
                        168     11.4                                      
                                   1 × 10.sup.4                     
                                         2.3                              
17* 95.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    3.000                                                 
                        172     11.8                                      
                                   5 × 10.sup.3                     
                                         2.2                              
18* 97.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0   190     8.8                                       
                                   5 × 10.sup.3                     
                                         10.1                             
19  97.898                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.001                                                 
                        205     9.0                                       
                                   9 × 10.sup.3                     
                                         9.2                              
20  97.799                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.100                                                 
                        215     10.4                                      
                                   1.1 × 10.sup.4                   
                                         9.1                              
21  95.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    2.000                                                 
                        230     11.9                                      
                                   1 × 10.sup.4                     
                                         8.0                              
22* 94.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    3.000                                                 
                        254     10.5                                      
                                   7 × 10.sup. 3                    
                                         6.9                              
23* 98.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0    90     8.0                                       
                                   4 × 10.sup.3                     
                                         4.0                              
24  98.898                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.001                                                 
                         93     9.1                                       
                                   8 × 10.sup.3                     
                                         2.8                              
25  98.799                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.100                                                 
                        100     11.4                                      
                                   9 × 10.sup.3                     
                                         2.6                              
26  96.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    2.000                                                 
                        120     12.0                                      
                                   1 × 10.sup.4                     
                                         2.5                              
27* 95.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    3.000                                                 
                        140     10.1                                      
                                   6 × 10.sup.3                     
                                         2.3                              
28* 97.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0   130     8.2                                       
                                   5 × 10.sup.3                     
                                         4.2                              
29  97.899                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.001                                                 
                        135     9.3                                       
                                   9 × 10.sup.3                     
                                         2.9                              
30  97.800                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.100                                                 
                        148     12.1                                      
                                   1.1 × 10.sup.4                   
                                         2.1                              
31  95.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    2.000                                                 
                        150     11.8                                      
                                   1.3 × 10.sup.4                   
                                         2.1                              
32* 94.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    3.000                                                 
                        164     10.0                                      
                                   6 × 10.sup.3                     
                                         2.0                              
33* 96.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0   180     8.0                                       
                                   6 × 10.sup.3                     
                                         10.0                             
34  96.899                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.001                                                 
                        190     8.5                                       
                                   8 × 10.sup.3                     
                                         9.2                              
35  96.800                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.100                                                 
                        204     8.9                                       
                                   1 × 10.sup.4                     
                                         9.0                              
36  94.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    2.000                                                 
                        210     9.4                                       
                                   1.3 × 10.sup.4                   
                                         8.8                              
37* 93.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    3.000                                                 
                        245     9.5                                       
                                   8 × 10.sup.3                     
                                         8.1                              
38* 94.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0    75     7.2                                       
                                   7 × 10.sup.3                     
                                         3.8                              
39  94.898                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.001                                                 
                         81     7.9                                       
                                   9 × 10.sup.3                     
                                         2.9                              
40  94.799                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.100                                                 
                         85     9.9                                       
                                   1 × 10.sup.4                     
                                         2.5                              
41  92.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    2.000                                                 
                        100     10.4                                      
                                   1.2 × 10.sup.4                   
                                         2.1                              
42* 91.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    3.000                                                 
                        115     11.0                                      
                                   6 × 10.sup.3                     
                                         2.0                              
43* 93.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0    82     7.6                                       
                                   7 × 10.sup.3                     
                                         3.9                              
44  93.899                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.001                                                 
                         85     8.3                                       
                                   9 × 10.sup.3                     
                                         2.9                              
45  93.800                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.100                                                 
                         97     10.1                                      
                                   1.1 × 10.sup.4                   
                                         2.6                              
46  91.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    2.000                                                 
                        108     11.2                                      
                                   1 × 10.sup.4                     
                                         2.2                              
47* 90.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    3.000                                                 
                        120     10.7                                      
                                   5 × 10.sup.3                     
                                         2.1                              
48* 92.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0    95     8.4                                       
                                   7 × 10.sup.3                     
                                         9.4                              
49  92.899                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.001                                                 
                        102     9.2                                       
                                   8 × 10.sup.3                     
                                         9.3                              
50  92.800                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.100                                                 
                        114     11.0                                      
                                   1 × 10.sup.4                     
                                         8.1                              
51  90.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    2.000                                                 
                        123     12.3                                      
                                   1 × 10.sup.4                     
                                         8.0                              
52* 89.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    3.000                                                 
                        147     10.4                                      
                                   7 × 10.sup.3                     
                                         7.4                              
53* 92.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0    40     4.0                                       
                                   6 × 10.sup.3                     
                                         6.2                              
54* 92.898                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.001                                                 
                         43     4.4                                       
                                   7 × 10.sup.3                     
                                         6.0                              
55* 92.799                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.100                                                 
                         49     4.5                                       
                                   8 × 10.sup.3                     
                                         5.8                              
56* 90.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    2.000                                                 
                         52     6.2                                       
                                   9 × 10.sup.3                     
                                         5.9                              
57* 89.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    3.000                                                 
                         69     5.8                                       
                                   7 × 10.sup.3                     
                                         5.8                              
58* 91.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0    49     4.4                                       
                                   6 × 10.sup.3                     
                                         10.2                             
59* 91.899                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.001                                                 
                         55     4.8                                       
                                   8 × 10.sup.3                     
                                         9.4                              
60* 91.800                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.100                                                 
                         62     5.5                                       
                                   8 × 10.sup.3                     
                                         9.1                              
61* 89.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    2.000                                                 
                         84     7.2                                       
                                   8 × 10.sup.3                     
                                         9.0                              
62* 88.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    3.000                                                 
                         93     6.1                                       
                                   7 × 10.sup.3                     
                                         8.5                              
63* 95.800                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    0.100                                                 
                        131     8.2                                       
                                   5 × 10.sup.3                     
                                         19.7                             
64* 92.900                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    3.000                                                 
                        249     9.1                                       
                                   4 × 10.sup.3                     
                                         18.0                             
__________________________________________________________________________
 *Comparison sample                                                       
 
    
     EXAMPLE 4 
     SrTiO 3 , Nb 2  O 5 , Ta 2  O 5 , MnO 2  and HfO 2  are made in a composition ratio shown in the below-mentioned Table 4, and mixing, forming and firings are carried out in a similar operation as the above-mentioned Example 1, and measurements are made in the similar conditions and results are shown in Table 4. 
     
                                           TABLE 4                                 
__________________________________________________________________________
Sample                                                                    
    Composition ratio (mol %)                                             
                        Characteristic value                              
No. SrTiO.sub.3                                                           
        Nb.sub.2 O.sub.5                                                  
            Ta.sub.2 O.sub.5                                              
                MnO.sub.2                                                 
                    HfO.sub.2                                             
                        V.sub.1 mA/mm (V)                                 
                                α                                   
                                   ε                              
                                         tan δ (%)                  
__________________________________________________________________________
 1* 99.795                                                                
        0.100                                                             
            0   0.100                                                     
                    0.005                                                 
                        1220    3.5                                       
                                   1 × 10.sup.3                     
                                         6.4                              
 2* 99.300                                                                
        0.100                                                             
            0   0.500                                                     
                    0.100                                                 
                        1470    5.6                                       
                                   2 × 10.sup.3                     
                                         11.8                             
 3* 99.899                                                                
        0.100                                                             
            0.001                                                         
                0   0    90     3.0                                       
                                   1 × 10.sup.3                     
                                         4.2                              
 4* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0   0.001                                                 
                        130     4.2                                       
                                   1 × 10.sup.3                     
                                         3.9                              
 5* 99.799                                                                
        0.100                                                             
            0.001                                                         
                0   0.100                                                 
                        135     4.9                                       
                                   2 × 10.sup.3                     
                                         3.3                              
 6* 97.899                                                                
        0.100                                                             
            0.001                                                         
                0   2.000                                                 
                        137     5.5                                       
                                   4 × 10.sup.3                     
                                         3.0                              
 7* 96.899                                                                
        0.100                                                             
            0.001                                                         
                0   3.000                                                 
                        194     5.4                                       
                                   3 × 10.sup.3                     
                                         4.5                              
 8* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0   100     5.7                                       
                                   4 × 10.sup.3                     
                                         4.1                              
9   99.897                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.001                                                 
                        135     8.6                                       
                                   8 × 10.sup.3                     
                                         3.7                              
10  99.798                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.100                                                 
                        142     9.7                                       
                                   9 × 10.sup.3                     
                                         3.2                              
11  97.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    2.000                                                 
                        160     9.8                                       
                                   9 × 10.sup.3                     
                                         2.9                              
12* 96.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    3.000                                                 
                        184     9.4                                       
                                   5 × 10.sup.3                     
                                         3.8                              
13* 98.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0   150     8.2                                       
                                   4 × 10.sup.3                     
                                         4.5                              
14  98.898                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.001                                                 
                        172     8.8                                       
                                   9 × 10.sup.3                     
                                         4.1                              
15  98.799                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.100                                                 
                        181     9.7                                       
                                   9 × 10.sup.3                     
                                         3.5                              
16  96.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    2.000                                                 
                        185     9.9                                       
                                   1.1 × 10.sup.4                   
                                         3.0                              
17* 95.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    3.000                                                 
                        202     9.1                                       
                                   6 × 10.sup.3                     
                                         7.2                              
18* 97.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0   190     8.8                                       
                                   5 × 10.sup.3                     
                                         10.1                             
19  97.898                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.001                                                 
                        208     8.0                                       
                                   9 × 10.sup.3                     
                                         10.0                             
20  97.799                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.100                                                 
                        219     8.6                                       
                                   1 × 10.sup.4                     
                                         9.2                              
21  95.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    2.000                                                 
                        224     8.5                                       
                                   1.1 × 10.sup.4                   
                                         8.9                              
22* 94.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    3.000                                                 
                        275     7.8                                       
                                   6 × 10.sup.3                     
                                         7.9                              
23* 98.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0    90     8.0                                       
                                   4 × 10.sup.3                     
                                         4.0                              
24  98.898                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.001                                                 
                        114     9.2                                       
                                   9 × 10.sup.3                     
                                         2.8                              
25  98.799                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.100                                                 
                        127     11.3                                      
                                   1 × 10.sup.4                     
                                         2.3                              
26  96.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    2.000                                                 
                        141     11.5                                      
                                   1.1 × 10.sup.4                   
                                         2.3                              
27* 95.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    3.000                                                 
                        176     9.0                                       
                                   6 × 10.sup.3                     
                                         6.4                              
28* 97.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0   130     8.2                                       
                                   5 × 10.sup.3                     
                                         4.2                              
29  97.899                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.001                                                 
                        159     9.2                                       
                                   9 × 10.sup.3                     
                                         3.0                              
30  97.800                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.100                                                 
                        169     12.0                                      
                                   9 × 10.sup.3                     
                                         2.6                              
31  95.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    2.000                                                 
                        175     11.4                                      
                                   1.1× 10.sup.4                    
                                         2.3                              
32* 94.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    3.000                                                 
                        200     9.1                                       
                                   7 × 10.sup.3                     
                                         5.5                              
33* 96.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0   180     8.0                                       
                                   6 × 10.sup.3                     
                                         10.0                             
34  96.899                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.001                                                 
                        205     8.0                                       
                                   7 × 10.sup.3                     
                                         9.6                              
35  96.800                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.100                                                 
                        221     8.0                                       
                                   7 × 10.sup.3                     
                                         9.1                              
36  94.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    2.000                                                 
                        245     8.1                                       
                                   8 × 10.sup.3                     
                                         8.9                              
37* 93.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    3.000                                                 
                        280     6.8                                       
                                   9 × 10.sup.3                     
                                         8.9                              
38* 94.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0    75     7.2                                       
                                   7 × 10.sup.4                     
                                         3.8                              
39  94.898                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.001                                                 
                        100     7.8                                       
                                   7 × 10.sup.3                     
                                         3.2                              
40  94.799                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.100                                                 
                        106     9.4                                       
                                   8 × 10.sup.3                     
                                         2.7                              
41  92.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    2.000                                                 
                        130     9.8                                       
                                   9 × 10.sup.3                     
                                         2.4                              
42* 91.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    3.000                                                 
                        147     8.9                                       
                                   4 × 10.sup.3                     
                                         3.6                              
43* 93.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0    82     7.6                                       
                                   7 × 10.sup.3                     
                                         3.9                              
44  93.899                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.001                                                 
                        109     8.5                                       
                                   9 × 10.sup.3                     
                                         2.8                              
45  93.800                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.100                                                 
                        125     10.3                                      
                                   1.1 × 10.sup.4                   
                                         2.7                              
46  91.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    2.000                                                 
                        135     10.2                                      
                                   1.2 × 10.sup.4                   
                                         2.5                              
47* 90.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    3.000                                                 
                        169     9.3                                       
                                   6 × 10.sup.3                     
                                         4.4                              
48* 92.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0    95     8.4                                       
                                   7 × 10.sup.3                     
                                         9.4                              
49* 92.899                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.001                                                 
                        135     9.0                                       
                                   7 × 10.sup. 3                    
                                         9.4                              
50* 92.800                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.100                                                 
                        142     10.1                                      
                                   8 × 10.sup.3                     
                                         9.1                              
51* 90.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    2.000                                                 
                        158     10.0                                      
                                   8 × 10.sup.3                     
                                         8.6                              
52* 89.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    3.000                                                 
                        211     8.2                                       
                                   4 × 10.sup.3                     
                                         9.3                              
53* 92.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0    40     4.0                                       
                                   6 × 10.sup.3                     
                                         6.2                              
54* 92.898                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.001                                                 
                         71     4.4                                       
                                   7 × 10.sup.3                     
                                         6.2                              
55* 92.799                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.100                                                 
                         78     4.3                                       
                                   6 × 10.sup.3                     
                                         6.0                              
56* 90.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    2.000                                                 
                         89     4.3                                       
                                   6 × 10.sup.3                     
                                         5.9                              
57* 89.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    3.000                                                 
                        128     4.0                                       
                                   6 × 10.sup.3                     
                                         7.9                              
58* 91.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0    49     4.4                                       
                                   6 × 10.sup.3                     
                                         10.2                             
59* 91.899                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.001                                                 
                         88     4.8                                       
                                   7 × 10.sup.3                     
                                         10.2                             
60* 91.800                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.100                                                 
                         91     5.1                                       
                                   6 × 10.sup.3                     
                                         10.1                             
61* 89.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    2.000                                                 
                        104     5.0                                       
                                   6 × 10.sup.3                     
                                         10.0                             
62* 88.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    3.000                                                 
                        144     4.2                                       
                                   4 × 10.sup.3                     
                                         10.0                             
63* 95.800                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    0.100                                                 
                        215     6.2                                       
                                   4 × 10.sup.3                     
                                         28.0                             
64* 92.900                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    3.000                                                 
                        272     5.0                                       
                                   4 × 10.sup.3                     
                                         22.4                             
__________________________________________________________________________
 *Comparison sample                                                       
 
    
     EXAMPLE 5 
     SrTiO 3 , Nb 2  O 5 , Ta 2  O 5 , MnO 2  and ZrO 2  are made in a composition ratio shown in the below-mentioned Table 5, and mixing, forming and firings are carried out in a similar operation as the above-mentioned Example 1, and measurements are made in the similar conditions and results are shown in Table 5. 
     
                                           TABLE 5                                 
__________________________________________________________________________
Sample                                                                    
    Composition ratio (mol %)                                             
                        Characteristic value                              
No. SrTiO.sub.3                                                           
        Nb.sub.2 O.sub.5                                                  
            Ta.sub.2 O.sub.5                                              
                MnO.sub.2                                                 
                    ZrO.sub.2                                             
                        V.sub.1 mA/mm (V)                                 
                                α                                   
                                   ε                              
                                         tan δ (%)                  
__________________________________________________________________________
 1* 99.795                                                                
        0.100                                                             
            0   0.100                                                     
                    0.005                                                 
                        1340    3.4                                       
                                   1 × 10.sup.3                     
                                         6.4                              
 2* 99.300                                                                
        0.100                                                             
            0   0.500                                                     
                    0.100                                                 
                        1520    5.5                                       
                                   2 × 10.sup.3                     
                                         11.4                             
 3* 99.899                                                                
        0.100                                                             
            0.001                                                         
                0   0    90     3.0                                       
                                   1 × 10.sup.3                     
                                         4.2                              
 4* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0   0.001                                                 
                        105     4.1                                       
                                   1 × 10.sup.3                     
                                         3.7                              
 5* 99.799                                                                
        0.100                                                             
            0.001                                                         
                0   0.100                                                 
                        112     4.8                                       
                                   2 × 10.sup.3                     
                                         3.0                              
 6* 97.899                                                                
        0.100                                                             
            0.001                                                         
                0   2.000                                                 
                        134     5.6                                       
                                   2 × 10.sup.3                     
                                         3.0                              
 7* 96.899                                                                
        0.100                                                             
            0.001                                                         
                0   3.000                                                 
                        174     5.7                                       
                                   3 × 10.sup.3                     
                                         4.5                              
 8* 99.898                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0   100     5.7                                       
                                   4 × 10.sup.3                     
                                         4.1                              
9   99.897                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.001                                                 
                        115     8.5                                       
                                   7 × 10.sup.3                     
                                         3.6                              
10  99.798                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    0.100                                                 
                        123     9.6                                       
                                   9 × 10.sup.3                     
                                         3.0                              
11  97.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    2.000                                                 
                        141     9.7                                       
                                   9 × 10.sup.3                     
                                         2.9                              
12* 96.799                                                                
        0.100                                                             
            0.001                                                         
                0.001                                                     
                    3.000                                                 
                        163     10.0                                      
                                   5 × 10.sup.3                     
                                         3.8                              
13* 98.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0   150     8.2                                       
                                   4 × 10.sup.3                     
                                         4.5                              
14  98.898                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.001                                                 
                        152     8.6                                       
                                   8 × 10.sup.3                     
                                         4.1                              
15  98.799                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    0.100                                                 
                        163     9.5                                       
                                   9 × 10.sup.3                     
                                         3.5                              
16  96.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    2.000                                                 
                        172     9.9                                       
                                   1 × 10.sup.4                     
                                         3.0                              
17* 95.899                                                                
        0.100                                                             
            0.001                                                         
                1.000                                                     
                    3.000                                                 
                        181     9.4                                       
                                   6 × 10.sup.3                     
                                         7.0                              
18* 97.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0   190     8.8                                       
                                   5 × 10.sup.3                     
                                         10.1                             
19  97.898                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.001                                                 
                        193     8.2                                       
                                   9 × 10.sup.3                     
                                         10.0                             
20  97.799                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    0.100                                                 
                        198     9.0                                       
                                   1 × 10.sup.4                     
                                         9.2                              
21  95.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    2.000                                                 
                        203     9.7                                       
                                   1.1 × 10.sup.4                   
                                         8.7                              
22* 94.899                                                                
        0.100                                                             
            0.001                                                         
                2.000                                                     
                    3.000                                                 
                        254     9.7                                       
                                   6 × 10.sup.3                     
                                         7.4                              
23* 98.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0    90     8.0                                       
                                   4 ×  10.sup.3                    
                                         4.0                              
24  98.898                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.001                                                 
                         97     9.1                                       
                                   8 × 10.sup.3                     
                                         2.8                              
25  97.799                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    0.100                                                 
                        104     11.2                                      
                                   9 × 10.sup.3                     
                                         2.4                              
26  96.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    2.000                                                 
                        126     11.7                                      
                                   1 × 10.sup.4                     
                                         2.3                              
27* 95.899                                                                
        0.100                                                             
            1.000                                                         
                0.001                                                     
                    3.000                                                 
                        155     10.0                                      
                                   6 × 10.sup.3                     
                                         6.1                              
28* 97.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0   130     8.2                                       
                                   5 × 10.sup.3                     
                                         4.2                              
29  97.899                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.001                                                 
                        143     9.1                                       
                                   9 × 10.sup.3                     
                                         3.0                              
30  97.800                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    0.100                                                 
                        151     11.9                                      
                                   1 × 10.sup.4                     
                                         2.4                              
31  95.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    2.000                                                 
                        155     11.5                                      
                                   1.1 × 10.sup.4                   
                                         2.2                              
32* 94.900                                                                
        0.100                                                             
            1.000                                                         
                1.000                                                     
                    3.000                                                 
                        174     9.4                                       
                                   7 × 10.sup.3                     
                                         5.4                              
33* 96.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0   180     8.0                                       
                                   6 × 10.sup.3                     
                                         10.0                             
34  96.899                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.001                                                 
                        194     8.1                                       
                                   7 × 10.sup.3                     
                                         9.4                              
35  96.800                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    0.100                                                 
                        209     8.2                                       
                                   7 × 10.sup.3                     
                                         8.9                              
36  94.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    2.000                                                 
                        231     8.7                                       
                                   8 × 10.sup.3                     
                                         8.8                              
37* 93.900                                                                
        0.100                                                             
            1.000                                                         
                2.000                                                     
                    3.000                                                 
                        258     8.9                                       
                                   5 × 10.sup.3                     
                                         8.8                              
38* 94.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0    75     7.2                                       
                                   7 × 10.sup.3                     
                                         3.8                              
39  94.898                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.001                                                 
                         83     7.6                                       
                                   8 × 10.sup.3                     
                                         2.9                              
40  94.799                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    0.100                                                 
                         94     9.2                                       
                                   9 × 10.sup.3                     
                                         2.4                              
41  92.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    2.000                                                 
                        110     9.9                                       
                                   1 × 10.sup.4                     
                                         2.3                              
42* 91.899                                                                
        0.100                                                             
            5.000                                                         
                0.001                                                     
                    3.000                                                 
                        126     10.0                                      
                                   6 × 10.sup.3                     
                                         3.6                              
43* 93.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0    82     7.6                                       
                                   7 × 10.sup.3                     
                                         3.9                              
44  93.899                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.001                                                 
                         93     8.3                                       
                                   9 × 10.sup.3                     
                                         2.7                              
45  93.800                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    0.100                                                 
                        100     10.1                                      
                                   1 × 10.sup.4                     
                                         2.6                              
46  91.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    2.000                                                 
                        107     10.0                                      
                                   9 × 10.sup.3                     
                                         2.6                              
47* 90.900                                                                
        0.100                                                             
            5.000                                                         
                1.000                                                     
                    3.000                                                 
                        134     9.7                                       
                                   5 × 10.sup.3                     
                                         4.2                              
48* 92.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0    95     8.4                                       
                                   7 × 10.sup.3                     
                                         9.4                              
49* 92.899                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.001                                                 
                        112     9.0                                       
                                   7 × 10.sup.3                     
                                         9.4                              
50* 92.800                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    0.100                                                 
                        124     10.1                                      
                                   7 × 10.sup.3                     
                                         9.1                              
51* 90.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    2.000                                                 
                        128     10.3                                      
                                   8 × 10.sup.3                     
                                         8.5                              
52* 89.900                                                                
        0.100                                                             
            5.000                                                         
                2.000                                                     
                    3.000                                                 
                        192     9.1                                       
                                   5 × 10.sup.3                     
                                         9.0                              
53* 92.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0    40     4.0                                       
                                   6 × 10.sup.3                     
                                         6.2                              
54* 92.898                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.001                                                 
                         58     4.5                                       
                                   6 × 10.sup.3                     
                                         6.0                              
55* 92.799                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    0.100                                                 
                         62     4.6                                       
                                   6 × 10.sup.3                     
                                         5.8                              
56* 90.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    2.000                                                 
                         69     6.2                                       
                                   7 × 10.sup.3                     
                                         5.8                              
57* 89.899                                                                
        0.100                                                             
            7.000                                                         
                0.001                                                     
                    3.000                                                 
                         99     4.9                                       
                                   5 × 10.sup.3                     
                                         7.1                              
58* 91.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0    49     4.4                                       
                                   6 × 10.sup.3                     
                                         10.2                             
59* 91.899                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.001                                                 
                         74     4.9                                       
                                   6 × 10.sup.3                     
                                         10.0                             
60* 91.800                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    0.100                                                 
                         80     5.5                                       
                                   6 × 10.sup.3                     
                                         9.9                              
61* 89.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    2.000                                                 
                         91     6.8                                       
                                   6 × 10.sup.3                     
                                         9.8                              
62* 88.900                                                                
        0.100                                                             
            7.000                                                         
                1.000                                                     
                    3.000                                                 
                        122     5.3                                       
                                   5 × 10.sup.3                     
                                         9.9                              
63* 95.800                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    0.100                                                 
                        197     6.5                                       
                                   4 ×  10.sup.3                    
                                         20.5                             
64* 92.900                                                                
        0.100                                                             
            1.000                                                         
                3.000                                                     
                    3.000                                                 
                        227     6.3                                       
                                   4 × 10.sup.3                     
                                         18.4                             
__________________________________________________________________________
 *Comparison sample                                                       
 
    
     As shown by Examples 1 to 5, Nb 2  O 5  and Ta 2  O 5  dissolve as solid solution into the crystal having SrTiO 3  as host material at the reduced firing and thereby to reduce specific resistance of the fired body by about 1.0 Ωcm by atomic valency controlling, and therefore, by refiring in the air it shows varistor characteristics such that high resitance layers are formed at the grain boundaries of the fired bodies. 
     And, Nb 2  O 5  is contained in TiO 2  in the material as inclusion, and is contained in 0.001-0.200 mol % in the raw material usually to be industrically refined. In case the SrTiO 3  is semiconductorized only with Nb 2  O 5  the specific resistance becomes rather high, and the characteristic is unstable though it shows the varistor characteristics. But by addition of Ta 2  O 5  to Nb 2  O 5 , the specific resistance can be lowered, and stable characteristics are obtainable. When the added amount of Ta 2  O 5  is too much, dissolution as solid solution of other additives is hindered, and accordingly 0.001-5.000 mol % of it is appropriate. 
     By making segregation at granule boundaries by addition of MnO 2 , the granule boundaries is changed to a high resistance value and the energy barrier of the granule boundaries. Therefore, by the addition of MnO 2 , the non-linearity exponent α becomes large and at the same time the varistor voltage becomes high. 
     Besides, by the addition of MnO 2  the high resistance region of the granule boundaries expands, and accordingly this means that thickness of the insulation layer increases, and thereby the dielectric constant decreases. 
     Since MnO 2  takes plural valency, there is a possibility of producing hopping conduction between different Mn valency. Therefore, when the amount of addition of MnO 2  increases the tan δ becomes large, to induce a cause of deterioration of the characteristic. Accordingly, as the amount of addition of MnO 2 , 0.001-2.000 mol % is appropriate. When La, Cu, Y, Mo, Pb and W are added, for the amount of MnO 2 , a range of 0.001 to 0.01 mole % is desirable for Na an amount of 0.001 to 0.02 mol % is desirable. 
     When at least one element selected from the group consisting of Ga, Pt, Tl, Si, Ti, Li, La, Cu, Y, Cs, Au, Mo, S, Be, Al, Na, K, Ca, Cd, In, Ba, Pb, Eu, Gd, Tb, Tm, Lu, Th, Ir, Os, Hf, Ru, Mg, Zr, Sn, Sb and W is added at the same time, it is possible to increase the dielectric constant and decrease the tan δ, without changing the non-linearity exponent α increased by MnO 2 , to greatly improve the characteristic, but the dielectric constant becomes small when the amount of addition becomes much; and accordingly 0.001-2.000 mol % is appropriate. 
     Though in the examples, only the cases where Ga, Pt, Tl, Si, Ti, Li, La, Cu, Y, Cs, Au, Mo, S, Be, Al, Na, K, Ca, Cd, In, Ba, Pb, Eu, Gd, Tb, Tm, Lu, Th, Ir, Os, Hf, Ru, Mg, Zr, Sn, Sb and W are added each as simple substance, it is confirmed that even when plural kinds of elements are added within the determined amount at the same time, the same effect is obtainable. 
     A noise filter as shown in FIG. 4 is constituted by using the elements 7 on which electrodes are provided by conductive material such as Ag and a coil 8, and noise input A shown in FIG. 5 is impressed, and thereby noise output B is obtained. 
     As is obvious from this, noise is sufficiently removed, and that number of components is decreased by combining the simple body element and a coil, and a miniaturization becomes possible. 
     POSSIBLE UTILIZATION IN INDUSTRY 
     As has been elucidated, according to the voltage-dependent non-linear resistance ceramic composition, absorption of surge impressed on the electric and electronic apparatuses and elimination of noise can be done by a single element, and it has many functions and can be miniaturized and is indispensable for protection of semiconductor product of the electric and electronic apparatuses, and practical utility thereof is extremely great.