Magnetoresistive head

A magnetoresistive head is disclosed which uses a crystalline soft magnetic film as an undercoat for a giant magnetoresistive film provided with at least one pair of ferro-magnetic films opposed to each other across a nonmagnetic intermediate layer or for an anisotropically magnetoresistive film. The crystalline soft magnetic film comprises a film which has as a main component thereof at least one element selected from the group consisting of Ni, Fe, and Co and simultaneously incorporates therein at least one element selected from the group consisting of Nb, Mo, V, W, Ti, Zr, Hf, and Ta and at least one element selected from the group consisting of Cr, Rh, Os, Re, Si, Al, Be, Ga, and Ge.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a magnetoresistive head to be used as in a 
magnetic disc device. 
2. Description of the Related Art 
Generally, the reading of information from a magnetic recording medium 
storing the information is implemented by a method which comprises moving 
a regenerating magnetic head possessed of a coil relative to the recording 
medium and causing the consequently generated electromagnetic induction to 
detect the voltage induced in the coil. It has been also known to use a 
magnetoresistive head (hereinafter referred to as "MR head") in effecting 
the reading of information. 
The MR head mentioned above operates by virtue of the phenomenon that the 
electric resistance of a certain kind of ferromagnetic element varies 
proportionately to the intensity of an external magnetic field and has 
been finding recognition as a head of high sensitivity fit for the 
magnetic recording medium. In recent years, owing to the trend of magnetic 
recording media toward decreased sizes and increased capacities, the 
relative speeds between the regenerating magnetic heads and the magnetic 
recording media during the course of reading of information have been 
decreasing. The expectation for an MR head which is capable of extracting 
a large output in spite of a small relative speed, therefore, has been 
gaining in depth. 
The MR head mentioned above is known in two types; the AMR head which uses 
a film of so-called Permalloy alloy or an Ni-Fe type alloy manifesting 
anisotropic magnetoresistance (hereinafter referred to as "AMR"), i.e. a 
phenomenon of producing a change in electric resistance depending on the 
angle formed between the direction of electric current and the direction 
of magnetization of a ferromagnetic layer and the GMR head which uses a 
spin valve film or an artificial lattice film having a laminated structure 
of a ferromagnetic layer and a nonmagnetic intermediate layer and 
manifesting giant magnetoresistance (hereinafter referred to as "GMR"). 
The AMR head operates on the principle that the resistivity, 
.rho.&lt;parallel&gt;, existing when the input current (sense current) and the 
magnetization M are parallel to each other and the resistivity, 
.rho.&lt;perpendicular&gt;, existing when they are perpendicular to each other 
are widely different, generally in this relationship, .rho.&lt;parallel&gt;&gt; 
.rho.&lt;perpendicular&gt;. Let .theta. stand for the angle formed between the 
current i and the magnetization M, and the resistivity .rho. of the AMR 
film will be expressed as follows. 
EQU .rho.=.rho.&lt;parallel&gt; cos.sup.2 +.rho.&lt;perpendicular&gt; sin.sup.2 .theta.. 
This resistivity .rho. is changed as shown in FIG. 6. When the AMR head is 
adopted as a regenerating head, therefore, the largest magnetoresistivity 
can be obtained by inclining the angle .theta. to the neighborhood of 45 
degrees. 
As a concrete example of the structure of the AMR head, the structure shown 
in FIG. 7 as published in Shingaku Giho, MR87-3 (1987), for example! may 
be cited. As shown in the diagram, an AMR film 1 is superposed through the 
medium of a nonmagnetic film 2 on a soft magnetic bias film 3. On the 
opposite terminal parts of the AMR film 1, antiferromagnetic bias films 4, 
4 and terminals 5, 5 for feeding a sense current are superposed. When the 
sense current is fed to the AMR head of this structure, a magnetic field 
produced by this current is exerted on the soft magnetic bias film 3. As a 
result, the soft magnetic bias film 3 is magnetized and a magnetic field 
produced in consequence of this magnetization can rotate the magnetization 
of the AMR film 1. The ratio of change in magnetoresistance of the AMR 
head of this structure is on the order of 3% even when this AMR head 
exhibits highly satisfactory soft magnetic property. Thus, the AMR head 
has the possibility of failing to cope with a decline which is suffered to 
occur in the magnetic field of the signal from the magnetic recording 
medium in consequence of an increase in recording density. 
The GMR head which uses such a GMR film 9 as a sandwich film composed of 
ferromagnetic layer 6/nonmagnetic intermediate layer 7/ferromagnetic layer 
8 as shown in FIG. 8, therefore, has come to attract growing interest. The 
observation that the GMR head of a certain type produced a ratio of change 
exceeding 10% in magnetoresistance effect at normal room temperature is 
reported in literature as in Journal of Japan Applied Magnetics Society, 
17, 91 (1993), for example!. 
The GMR head, unlike the AMR head, shows a low magnetoresistance effect 
when the magnetizations contained in the ferromagnetic layers 6, 8 are 
parallel to each other and a high magnetoresistance effect when the 
magnetizations are antiparallel to each other. The structure which is 
shown in FIG. 8 is such that the magnetization of the upper ferromagnetic 
layer 8 is fixed by an antiferromagnetic exchange bias film 10 and the 
magnetization of the lower ferromagnetic layer 6 moves freely. The GMR 
film 9 is enabled infallibly to draw in an input magnetic flux by having a 
magnetic undercoating film 11 disposed in contact with the ferromagnetic 
layer 6. Since the magnetic undercoating film 11 is ferromagnetically 
coupled with the ferromagnetic layer 6, the magnetization of the 
ferromagnetic layer 6 is rotated in accompany with the rotation of the 
magnetization of the magnetic undercoating film 11. Incidentally, 
ferromagnetic bias films 12, 12 are disposed underneath the opposite 
terminal parts of the magnetic undercoating film 11. 
Since the AMR head and the GMR head alike effect the reading of recorded 
information by extracting a change in reluctance due to the magnetic field 
of a signal, they introduce a sense current as an input and emit a 
corresponding change in reluctance in the form of a change in voltage. 
Since the soft magnetic bias film 3 and the magnetic undercoating film 11 
are disposed in indirect or direct contact with the AMR film 1 or the GMR 
film 9, the sense current is fed also to the soft magnetic films 3 and 11. 
Since the amounts of electric current which flow into the soft magnetic 
films 3 and 11, namely the amounts of shunt electric current, deserve no 
complete disregard, the changes in reluctance are smaller than when the 
amounts of shunt electric current are nil. If the reluctances of the soft 
magnetic films 3 and 11 are equal to those of the AMR film 1 and the GMR 
film 9, the rates of change in magnetic reluctance will be halved. In the 
light of all these factors, the reluctances of the soft magnetic films 3, 
11 ought to be large. 
More often than not, the soft magnetic films 3, 11 are formed underneath 
the AMR film 1 or the GMR film 9 as shown in FIG. 7 and FIG. 8. In the 
configuration of this kind, the soft magnetic films 3, 11 are destined to 
affect the orienting properties of the AMR film 1 and the GMR film 9. 
Generally, in such circumstance, it is made possible to improve the device 
characteristics by endowing the soft magnetic films 3 and 11 with a 
function of enhancing the fcc (111) orienting properties of the AMR film 1 
and the GMR film 9. 
Attempts, therefore, have been being made to enhance the fcc (111) 
orienting property of the GMR film 9 by using Permalloy films for the soft 
magnetic films 3, 11. The GMR film 9 has not yet acquired a fully 
satisfactory ratio of change in magnetic reluctance in spite of the 
efforts. This fact indicates that the fcc (111) orienting property due to 
the Permalloy films is still insufficient. 
For the purpose of improving the characteristics of the soft magnetic films 
3, 11, there may be conceived an idea of using NiFe, for example, as a 
main component and causing this main component to incorporating additive 
elements therein. In fact, a report purporting to demonstrate the 
effectiveness of the incorporation of Nb, Zr, etc. as additive elements 
for enhancing the resistivity is reported in literature J. Appl. Phys., 
69, 5631 (1991)!. The incorporation of such additive elements, however, 
brings about no notable improvement in the fcc (111) orienting property 
which constitutes another important property. If the amount of such 
additive elements to be incorporated is increased beyond a certain level, 
the orienting property will be degraded rather than improved and the 
saturation magnetization will be likewise lowered. 
As described above, while ideas concerning the exaltation of resistivity of 
the soft magnetic films destined to serve as undercoats for the AMR film 
and the GMR film have been proposed heretofore, no thoroughgoing study has 
ever been made on the improvement of the orienting properties of the AMR 
film and the GMR film. A soft magnetic film which fulfills both the 
exaltation of the resistivity and the improvement of the fcc (111) 
orienting property has not yet been perfected. 
SUMMARY OF THE INVENTION 
The present invention, produced for the sake of overcoming the drawbacks 
encountered to date as described above, has an object of providing a 
magnetoresistive head having the magnetoresistive ratio and other 
characteristics improved by increasing the resistivity of a soft magnetic 
film deposited between a substrate and an MR film and, at the same time, 
exalting the fcc (111) preferred orientation. 
The first magnetoresistive head according to this invention is a 
magnetoresistive head comprising a giant magnetoresistive film having at 
least a pair of ferromagnetic layers opposed to each other and a 
nonmagnetic intermediate layer disposed between the pair of ferromagnetic 
layers, and a crystalline soft magnetic film disposed as an undercoat in 
contact with at least the surface of one of the pair of ferromagnetic 
layers, wherein the crystalline soft magnetic film essentially consisting 
of at least one element selected from the group consisting of Ni, Fe and 
Co as a main component, at least one element selected from the group 
consisting of Nb, Mo, V, W, Ti, Zr, Hf and Ta, and at least one element 
selected from the group consisting of Cr, Rh, Os, Re, Si, Al, Be, Ga and 
Ge. 
The second magnetoresistive head according to this invention is a 
magnetoresistive head comprising an anisotropic-magnetoresistive film, and 
a crystalline soft magnetic film disposed in contact directly with the 
anisotropic-magnetoresistive film or indirectly through the medium of a 
nonmagnetic film as an undercoat of the anisotropic-magnetoresistive film, 
wherein the crystalline soft magnetic film essentially consisting of at 
least one element selected from the group consisting of Ni, Fe and Co as a 
main component, at least one element selected from the group consisting of 
Nb, Mo, V, W, Ti, Zr, Hf and Ta, and at least one element selected from 
the group consisting of Cr, Rh, Os, Re, Si, Al, Be, Ga and Ge. 
The magnetoresistive device according to this invention is a 
magnetoresistive device comprising a laminated film comprising first and 
second ferromagnetic layers and a nonmagnetic layer disposed between the 
first and second ferromagnetic layers, and a magnetic film of a NiFe alloy 
disposed on the laminated film in contact with one of the first and second 
ferromagnetic layers, wherein one of the first and second ferromagnetic 
layers comprises Co or a CoFe alloy, and the NiFe alloy comprises at least 
one element selected from the group consisting of Nb, Mo, V, W, Ti, Zr, Hf 
and Ta, and at least one element selected from the group consisting of Cr, 
Rh, Os, Re, Si, Al, Be, Ga and Ge. 
The crystalline soft magnetic film to be used in the present invention uses 
as a main component thereof at least one element selected from the group 
consisting of Ni, Fe, and Co and also incorporates therein an M element 
capable of forming a grain boundary for the sake of increasing the 
resistivity and improving soft magnetic property. As the main component of 
crystalline soft magnetic film, a NiFe alloy is desirable. The NiFe alloy 
has a composition represented by the general formula Ni.sub.100-b 
Fe.sub.b, wherein b stands for an atomic % and is a number satisfying 
0&lt;b.ltoreq.50, more preferably, 10.ltoreq.b.ltoreq.40. As a concrete 
example of the M element, at least one element selected from the group 
consisting of Nb, Mo, V, W, Ti, Zr, Hf, and Ta may be cited. When the 
amount of the M element to be added is continuously increased, though the 
resistivity increases proportionately, the grain boundary becomes finer 
and the film ultimately has a nearly amorphous texture. From the viewpoint 
of keeping the preferred orientation, it is not proper to increase the 
amount of the M element to an unduly large amount. The characteristics 
aimed at, therefore, cannot be attained by only the addition of the M 
element. 
Accordingly, in this invention, it is required to incorporate an additional 
M' element which, by forming a solid solution with the main component 
mentioned above in the crystal grains, contributes to exalting the fcc 
(111) preferred orientation and the increase in resistivity due to scatter 
of electrons near the Fermi surface unlike the formation of a grain 
boundary. As a result, the crystalline soft magnetic film is enabled to 
have the resistivity thereof exalted to a level exceeding 100 
.mu..OMEGA.cm, for example, and at the same time acquire an outstanding 
soft magnetic property with by high permeability and a highly desirable 
fcc (111) preferred orientation. As a concrete example of the M' element, 
at least one element selected from the group consisting of Cr, Rh, Os, Re, 
Si, Al, Be, Ga, and Ge may be cited. Enough of an increase of an 
resistivity of the crystalline soft magnetic film, however, cannot be 
attained by only the addition of the M' element. 
When the M element and the M' element mentioned above are added each in an 
unduly large amount, the excesses thereof will go to degrade the fcc (111) 
preferred orientation and the soft magnetic property. Appropriately, 
therefore, the amount of the M element and that of the M' element to be 
added are not more than 20 at. %. If their amounts are each less than 0.1 
at. %, the elements added at all will fail to manifest their effects. The 
crystalline soft magnetic film to be used in this invention, therefore, 
appropriately has a composition substantially represented by the general 
formula: 
EQU T.sub.1-(x+y) M.sub.x M'.sub.y 
wherein T stands for at least one element selected from the group 
consisting of Ni, Fe, and Co, M for at least one element selected from the 
group consisting of Nb, Mo, V, W, Ti, Zr, Rf, and Ta, and M' for at least 
one element selected from the group consisting of Cr, Rh, Os, Re, Si, Al, 
Be, Ga, and Ge, and x and y stand for numerals respectively satisfying the 
expressions, 0.001.ltoreq..times..ltoreq.0.200 and 
0.01.ltoreq.y.ltoreq.0.200. 
Appropriately, the thickness of the crystalline soft magnetic film is in 
the approximate range of 1 to 100 nm. If the thickness of the crystalline 
soft magnetic film is less than 1 nm, the crystallinity of the film will 
be degraded and the preferred orientation thereof will decrease. If this 
thickness conversely exceeds 100 nm, the possibility ensues that the 
amount of the shunt current suffered to flow into the crystalline soft 
magnetic film will increase and the change in reluctance of the 
magnetoresistive head will decrease even when the this film happens to 
have a high resistivity. For the purpose of this invention, the 
crystalline soft magnetic film is only required to possess a soft magnetic 
property such that the coercive force thereof is less than 800 A/m, 
preferably not more than about 80 A/m. The crystallinity of the film can 
be easily measured by means of X-ray diffraction. 
Further, in the present invention, it is advantageous to heighten the 
crystallinity of the crystalline soft magnetic film by forming a 
nonmagnetic metal film essentially consisting of at least one element 
selected from the group consisting of Ti, Ta, Zr, Cr, Nb, and Hf between a 
substrate and this crystalline soft magnetic film. By having the 
nonmagnetic metal film disposed as an undercoat in contact with the 
crystalline soft magnetic film, the crystal growth with good crystallinity 
of crystalline soft magnetic film is achieved even when the thickness is 
so small as to fall in the neighborhood of 1 nm, and consequently an 
exalted fcc (111) preferred orientation. The thickness of the nonmagnetic 
metal film appropriately is in the approximate range of 1 to 100 nm. If 
the thickness of the nonmagnetic metal film is less than 1 nm, it will be 
difficult to improve the crystallinity of the crystalline soft metal film 
to a sufficiently high level. Conversely, if this thickness exceeds 100 
nm, the possibility arises that the amount of the shunt current suffered 
to flow into the film will increase and the magnetoresistive change of the 
magnetoresistive head will unduly decrease. 
The first magnetoresistive head of this invention has superposed on the 
crystalline soft magnetic film of the quality described above a giant 
magnetoresistive film (GMR film) having at least one pair of ferromagnetic 
films opposed to each other and a nonmagnetic intermediate layer disposed 
between the pair of ferromagnetic films in such a manner that at least one 
of the ferromagnetic layers may contact the crystalline soft magnetic 
film. 
The ferromagnetic film materials which are effectively used for the 
ferromagnetic layers mentioned above include Co, CoFe, CoNi, NiFe, 
Sendust, NiFeCo, and Fe.sub.8 N, for example. These ferromagnetic films 
appropriately have a thickness in the range of 1 to 20 nm. 
The ferromagnetic layer disposed on said crystalline soft magnetic film 
comprises a fcc (111) oriented ferromagnetic layer. The ferromagnetic 
layer comprising Co or a Co alloy is preferable. More preferably the 
ferromagnetic layer comprising a Co alloy is used. A desirable Co alloy is 
a CoFe alloy having a composition represented by the general formula 
Co.sub.100-a Fe.sub.a, wherein a stands for an atomic % and is a number 
satisfying 0&lt;a.ltoreq.50. More preferably, a is a number satisfying 
5.ltoreq.a.ltoreq.40. 
The materials which are effectively used for the nonmagnetic film include 
such nonmagnetic metals as Mn, Cu, Al, Pd, Pt, Rh, Ru, Ir, Au, and Ag and 
such alloys as CuPd, CuPt, CuAu, and CuNi. Appropriately, the nonmagnetic 
film has a thickness in the range of 0.5 to 20 nm. 
Owing to the adoption of the structure described above, the GMR film enjoys 
an exalted fcc (111) preferred orientation and, as a result, the GMR film 
is enabled to be improved in the soft magnetic property and the 
magnetoresistive ratio. Further, the fact that the resistivity of the 
crystalline soft magnetic film is high allows a marked decrease in the 
amount of the current which is suffered to flow into the crystalline soft 
magnetic film. 
The magnetoresistive head which is constructed with the GMR film of the 
quality mentioned above, therefore, is enabled to be improved in the 
magnetoresistive ratio of the head and also in the MR sensitivity to be 
manifested. Wherein the MR sensitivity is represented by The ratio of 
change in MR(%)! / Magnetic field (Oe)!. The giant magnetoresistive films 
which are used effectively herein include such so-called spin valve films 
as Co/Cu/Co, CoFe/Cu/CoFe, and NiFe/Cu/NiFe and such artificial lattice 
films as (Fe/Cr).sub.n laminate film and (Co/Cu).sub.n laminate film, for 
example. 
The second magnetoresistive head of this invention is formed by using the 
crystalline soft magnetic film of the quality mentioned above as a soft 
magnetic bias film, for example, and superposing thereon either directly 
or through the medium of a nonmagnetic film the ferromagnetic film (AMR 
film) manifesting anisotropic magnetoresistance. By adopting this 
structure, the fcc (111) preferred orientation of the AMR film can be 
exalted and the magnetoresistive ratio thereof can be increased. Further, 
since the soft magnetic bias film has high resistivity, the amount of the 
current suffered to flow into this film can be decreased to a great 
extent. The AMR film of such quality, like the GMR film, enables the 
magnetoresistive head formed therewith to be improved in the 
magnetoresistive ratio and in the MR sensitivity as well. 
As the anisotropically magnetoresistive film, the film of such a Permalloy 
alloy as an Fe-Ni base alloy is used. Then, for the nonmagnetic metal film 
to be optionally interposed between the AMR film and the crystalline soft 
magnetic film, Ti, Ta, Zr, Pt, Au, Ag, Cu, TaN, SiO.sub.2 and Pd can be 
used. In these materials, Ti, Ta, and Zr prove preferable with 
consideration to the higher resistivity of the nonmagnetic film and Pt, 
Au, Ag, Cu, and Pd prove preferable from the viewpoint of the preferred 
orientation. In the case of Pt, Au, Ag, Cu, and Pd, they may be alloyed 
with Ni, Fe, Co, Cr, Mn, etc. for the sake of enhancing the resistivity of 
the nonmagnetic film. Appropriately, this nonmagnetic film has a thickness 
of not more than 100 nm in order to suppress the amount of the shunt 
current suffered to flow into the film. 
In the first and second magnetoresistive head, the magnetoresistive head of 
this invention may comprise an amorphous magnetic layer, as an undercoat 
of the magnetic film. 
In the magnetoresistive device of this invention, the NiFe alloy may 
further comprise Co. In addition, the NiFe alloy has a composition 
represented by the general formula, T.sub.1-(x+y) M.sub.x M'.sub.y, 
wherein T stands for Ni and Fe, M stands for at least one element selected 
form the group consisting of Nb, Mo, V, W, Ti, Zr, Hf and Ta, M' stands 
for at least one element selected from the group consisting of Cr, Rh, Os, 
Re, Si, Al, Be, Ga and Ge, and x and y stand for numerals respectively 
satisfying the expressions, 0.001.ltoreq..times..ltoreq.0.200 and 
0.01.ltoreq.y.ltoreq.0.200. 
In the above composition, preferable, T has a composition represented by 
the general formula, Ni.sub.100-b Fe.sub.b, wherein b stands for an atomic 
% and is a number satisfying 0&lt;b.ltoreq.50. 
One of the first and second ferromagnetic layers of the magnetoresistive 
device comprises a fcc (111) oriented film of Co or a Co alloy. This Co 
alloy may have a composition represented by the formula of Co.sub.100-a 
Fe.sub.a, wherein a stands for an atomic % and is a number satisfying 
5.ltoreq.a.ltoreq.40. 
Further, the magnetoresistive device of this invention may dispose a 
nonmagnetic metal film of at least one element selected from the group 
consisting of Ti, Ta, Zr, Cr, Nb and Hf, as an undercoat of the magnetic 
film. 
The magnetoresistive device of this invention may dispose an amorphous 
magnetic layer, as an undercoat of the magnetic film. 
The magnetoresistive device of this invention may use as, for example, a 
sensor, a memory and the likes.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Now, the embodiments of this invention will be described below. 
EXAMPLE 1 
First, on an Si substrate provided in advance thereon with a thermally 
oxidized film 100 nm in thickness, a crystalline soft magnetic film of a 
composition of Ni.sub.73.7 Fe.sub.19.0 Nb.sub.3.8 Cr.sub.3.5 resulting 
from the addition of Nb and Cr to a NiFe Permalloy was superposed in a 
thickness of 10 nm. Then, on this crystalline soft film used as a soft 
magnetic undercoating film, a laminate film of CoFePd(4 nm)/Cu(2.5 
nm)/CoFePd(4 nm) was superposed as a spin valve film. Further on the spin 
valve film, an FeMn alloy film was superposed in a thickness of 15 nm as 
an antiferromagnetic exchange bias film. A pair of CoPt films of a 
thickness of 20 nm was formed in advance as a ferromagnetic bias film 
underneath the opposite terminal parts of the soft magnetic undercoating 
film. Then, a GMR head was completed by superposing a pair of terminals 
made of Ta/Cu/Ta and adapted to feed a sense current on the 
antiferromagnetic exchange bias film. This GMR head had a specific 
structure identical to that of a conventional GMR head shown in FIG. 8. 
COMATIVE EXAMPLE 1 
As the conventional GMR head, a GMR head (Comparative Example 1) was 
manufactured by using a NiFe alloy film as a crystalline soft magnetic 
film and superposing a laminate film of NiFe(10 nm)/CoFePd(4 nm)/Cu(2.5 
nm)/CoFePd(4 nm)/FeMn(15 nm) on the same thermally oxidized Si substrate 
as used in Example 1. 
The GMR heads of Example 1 and Comparative Example 1 obtained as described 
above were tested for fcc (111) orientation property. FIG. 1 is the 
profile of the neighborhood of (111) peak obtained by the X-ray 
diffraction of the GMR film in the GMR head of Example 1 and FIG. 2 is the 
profile of the neighborhood of (111) peak similarly obtained of the GMR 
film in the GMR head of Comparative Example 1. 
It is clearly noted from FIG. 1 and FIG. 2 that the GMR head of Example 1 
obtained a (111) peak strength more than 10 times that obtained by the 
conventional GMR head. Since the peaks forming shoulders are based on the 
interference in the laminate layers and no other fcc peak like a (200) 
peak was found around a wide range of 2.theta. from 40.degree. to 
90.degree., the (111) peak intensity was used for evaluating the fcc (111) 
orientation property. 
In the GMR heads of Example 1 and Comparative Example 1 mentioned above, 
the NiFeNbCr film used as the soft magnetic undercoating film in the GMR 
head of Example 1 had a resistivity of 110 .mu..OMEGA.cm and the NiFe 
Permalloy used in Comparative Example 1 had a resistivity of 30 
.mu..OMEGA.cm. The comparison clearly indicates that the addition of the 
two elements, M element and M' element, resulted in enhancing the 
magnitude of resistivity while improving the fcc (111) preferred 
orientation. 
As to the magnetoresistive ratio which constitutes one of the important 
characteristics, the GMR head of Example 1 showed a highly satisfactory 
magnitude exceeding 10% (10.3%) while the GMR head of Comparative Example 
1 showed a magnitude of 2.5%. The former GMR head showed an improved MR 
sensitivity of 2.0% as compared with the sensitivity of 1.0% shown by the 
latter GMR head. It is safely concluded that these better results 
originated in the improvements achieved by the GMR film and the soft 
magnetic film superposed thereon with large resistivity and the fcc (111) 
preferred orientation and that the improvement in the fcc (111) preferred 
orientation particularly contributed to enhancing these properties. 
The use of the crystalline soft magnetic film which resulted from the 
incorporation of two elements different in quality into the main component 
such as an NiFe alloy allowed the GMR head to acquire improved 
characteristics as described above. This fact demonstrates the usefulness 
of this invention. The results described above are shown in Table 1 and 
Table 2. 
The relation between the thickness and the ratio of change in 
magnetoresistance obtained of the crystalline soft magnetic film made of 
the NiFeNbCr film mentioned above is shown in FIG. 3. It is noted from 
FIG. 3 that the thickness of the crystalline soft magnetic film 
appropriately falls in the range of 1 to 100 nm. If the thickness of the 
crystalline soft magnetic film is less than 1 nm, the film will not 
acquire a fully satisfactory magnetoresistive ratio because the film is 
still in the stage of initial growth and, therefore, undergoes 
crystallization with difficulty and acquires an inferior orientation 
property. Conversely, if the thickness of the crystalline soft magnetic 
film exceeds 100 nm, the film will tend to suffer a decrease in the ratio 
of change in magnetoresistance because the amount of the shunt current 
cannot be sufficiently decreased. 
As to the proportions of the components of NiFe as the main component of 
the present example, it is appropriate for the proportion of Ni to be in 
the range of from 60 at. % to 90 at. % and that of Fe in the range of from 
40 at. % to 10 at. % in due respect of the balance between the soft 
magnetic property and the magnitude of the magnetic moment. 
A ternary alloy of NiFeCo may be used as the main component. If the 
proportion of Co to be incorporated exceeds 50 at. %, however, the excess 
of Co will go to increase excessively the coercive force, Hc, and 
consequently impair the soft magnetic property. 
Incidentally, the present example used the Si substrate which was provided 
with a thermally oxidized film. When a GMR head was manufactured by 
following the procedure of this example while using an alumina film formed 
on an altic substrate instead, it was confirmed to produce the same 
effect. 
EXAMPLE 2 
As compared with Example 1 representing a case of growing a crystalline 
soft magnetic film directly on a Si substrate provided in advance thereon 
with a thermally oxidized film or an alumina film, for this Example 2, a 
Co.sub.87 Zr.sub.5.5 Nb.sub.7.5 film was formed in a thickness of 10 nm as 
an amorphous magnetic undercoating film for a crystalline soft magnetic 
film and a crystalline soft magnetic film of a composition of Ni.sub.73.7 
Fe.sub.19.0 Nb.sub.3.8 Cr.sub.3.5 was superposed in a thickness of 5 nm on 
the undercoating film for the sake of further enhancing the fcc (111) 
preferred orientation. Then, a spin valve film and an antiferromagnetic 
exchange bias film were superposed thereon in the same manner as in 
Example 1. 
The GMR film in the GMR head manufactured as described above was tested for 
the fcc (111) orientation property. As a result, it was confirmed that the 
intensity of the fcc (111) peak was nearly equal to that obtained in 
Example 1. This fact indicates that, notwithstanding the thickness of the 
crystalline soft magnetic film was one half of that of Example 1, the GMR 
film showed this high fcc (111) preferred orientation. 
In this Example 2, in spite of the inevitable flow of the shunt current 
into the magnetic undercoating film, the fcc (111) orientation was so high 
that the ratio of change in GMR was 11% and the GMR sensitivity was 
2.2%/Oe, i.e. magnitudes higher than those obtained in Example 1. The 
magnetic undercoating film used in this example cooperated with the 
crystalline soft magnetic film to permit impartation of high soft 
magnetism. 
The relation between the thickness and the ratio of change in 
magnetoresistance (ratio of change in GMR) obtained of the crystalline 
soft magnetic film provided with a Co.sub.87 Zr.sub.5.5 Nb.sub.7.5 
magnetic under-coating film is shown in FIG. 4. This diagram, unlike that 
of FIG. 3, clearly shows that a high magnetoresistive ratio was obtained 
when the film thickness was in the neighborhood of 5 nm and that the 
magnetic undercoating film aided in the growth of the crystalline soft 
magnetic film. 
For the magnetic undercoating film which exalted the fcc (111) preferred 
orientation of this crystalline soft magnetic film, amorphous CoZrNb based 
or a microcrystalline FeN based alloy like FeZrN manifested the same 
effect. 
EXAMPLE 3 
Example 2 cited above represents a case of using a single-layer magnetic 
coating film as the magnetic undercoating film for enhancing the fcc (111) 
preferred orientation of the crystalline soft magnetic film. A multilayer 
film consisting of a nonmagnetic undercoating film and a magnetic 
undercoating film may be used in the place of the single-layer magnetic 
under-coating film mentioned above. 
In this Example 3, a crystalline soft magnetic film of a composition of 
Ni.sub.73.7 Fe.sub.19.0 Nb.sub.3.8 Cr.sub.3.5 was formed in a thickness of 
5 nm on an undercoat obtained by forming a Co.sub.87 Zr.sub.5.5 Nb.sub.7.5 
film in a thickness of 5 nm on a nonmagnetic film of Ta of a thickness of 
5 nm. Then, a spin valve film and an antiferromagnetic exchange bias film 
were formed thereon in the same manner as in Example 1. 
The GMR film in the GMR head manufactured as described above was tested for 
the fcc (111) preferred orientation. As a result, it was confirmed that 
the intensity of the fcc (111) peak was nearly equal to that obtained in 
Example 1. The use of the two-layer undercoating film as mentioned above 
allowed the fcc (111) orientation property to remain at a high level and 
produced consequently a ratio of change in GMR of 11% and a sensitivity of 
GMR of 2.2%/Oe, i.e. magnitudes nearly equal to those obtained in Example 
2. Further in the present example, the total magnetic moment was smaller 
than that of Example 2. The head ultimately produced, therefore, showed an 
increase in the magnetic flux from the medium and could be expected to 
enjoy an increased output. 
For the nonmagnetic undercoating film in this example, Ti, Zr, Cr, Nb, and 
Hf were confirmed to produce the same effect as Ta. Appropriately, the 
nonmagnetic undercoating film has a thickness in the range of 1 nm to 10 
nm. If the thickness is less than 1 nm, the film will not be easily formed 
as a single-layer film. If this thickness exceeds 10 nm, the amount of the 
shunt current suffered to flow in will increase. If the thickness of the 
magnetic undercoating film is not more than 1 nm, the film will not be 
easily formed as a single-layer film. If the thickness exceeds 10 nm, the 
amount of the shunt current will unduly increase. If the thickness is 
larger, then the nonmagnetic undercoating film will be no longer 
necessary. 
The head of this example may use the structure shown in FIG. 8. This 
structure, however, has the possibility of cut off of the exchange 
coupling between a ferromagnetic bias film 12 and a soft magnetic film 11 
by the nonmagnetic undercoating film. It is, therefore, preferable for the 
nonmagnetic undercoating film 13 to be disposed underneath the 
ferromagnetic bias film 12 as shown in FIG. 9. 
The additive elements for the crystalline soft magnetic film which were 
indicated in the preceding Examples 2 and 3 were found to produce the same 
effects with respect to the elements which will be indicated in the 
following Examples 4 through 34. 
EXAMPLES 4 TO 34 AND COMATIVE EXAMPLES 2 TO 13 
GMR heads were manufactured by following the procedure of Example 1 while 
using crystalline soft magnetic films of varying compositions shown in 
Table 1 and Table 2 in the place of the crystalline soft magnetic film of 
Example 1. For comparison with this invention, GMR heads (Comparative 
Examples 2 through 9) using crystalline soft magnetic films resulting from 
the sole incorporation of an M element in the main component of a NiFe 
alloy and GMR heads (Comparative Examples 10 through 13) using crystalline 
soft magnetic films resulting from the sole incorporation of an M' element 
in the main component of a NiFe alloy were manufactured in the same manner 
as in Example 1. 
The crystalline soft magnetic films in the GMR heads of the examples and 
the comparative examples mentioned above were tested for the (111) peak 
intensity and the magnitude of resistivity and, at the same time, the GMR 
heads were tested for the ratio of change in GMR and the GMR sensitivity. 
The results are shown in Table 1 and Table 2. 
In the Table 1 and Table 2, NiFe as a main component of the crystalline 
soft magnetic film consists of 80 at. % of Ni and 20 at. % of Fe. In the 
following examples, the same NiFe was used. 
TABLE 1 
__________________________________________________________________________ 
GMR 
COMPOSITION (111) RATIO 
GMR 
MAIN PEAK OF SENSI- 
COMPO- INTEN- 
.rho. 
CHANGE 
TIVITY 
NENT M (at %) 
M' (at %) 
SITY 
(.mu..OMEGA.cm) 
(%) (%/Oe) 
__________________________________________________________________________ 
EXAMPLE 
__________________________________________________________________________ 
1 NiFe Nb(3.8) 
Cr(3.5) 
2500 
110 10.3 2.0 
4 NiFe Mo(4.8) 
Cr(3.5) 
2600 
105 10.5 1.8 
5 NiFe V(2.6) 
Cr(3.5) 
2400 
100 11.0 2.2 
6 NiFe W(1.7) 
Cr(3.5) 
2500 
120 9.8 1.6 
7 NiFe Ti(2.7) 
Cr(3.5) 
3000 
115 10.2 1.7 
8 NiFe Zr(1.9) 
Cr(3.5) 
3400 
100 10.6 2.3 
9 NiFe Hf(2.4) 
Cr(3.5) 
2600 
110 10.9 1.8 
10 NiFe Ta(3.2) 
Cr(3.5) 
2100 
103 11.1 1.5 
11 NiFe Nb(3.4) 
Rh(5.0) 
2400 
107 10.1 2.6 
12 NiFe Mo(4.6) 
Rh(5.0) 
3400 
112 9.5 1.1 
13 NiFe V(2.4) 
Rh(5.0) 
2800 
106 9.8 1.2 
14 NiFe W(1.8) 
Rh(5.0) 
3200 
104 10.2 1.6 
15 NiFe Ti(2.6) 
Rh(5.0) 
2600 
103 11.3 1.7 
16 NiFe Zr(1.7) 
Rh(5.0) 
2900 
110 10.4 1.3 
17 NiFe Hf(2.2) 
Rh(5.0) 
3100 
100 10.6 2.0 
18 NiFe Ta(3.4) 
Rh(5.0) 
2600 
106 10.2 2.0 
19 NiFe Nb(3.2) 
Os(4.1) 
2700 
104 10.1 2.4 
20 NiFe Mo(4.4) 
Os(4.1) 
2800 
108 10.9 2.3 
21 NiFe V(2.2) 
Os(4.1) 
2400 
102 10.7 2.0 
22 NiFe W(1.6) 
Os(4.1) 
2600 
106 9.6 1.8 
23 NiFe Ti(2.1) 
Os(4.1) 
2500 
113 10.4 1.4 
24 NiFe Zr(1.5) 
Os(4.1) 
2400 
104 10.2 1.7 
25 NiFe Hf(2.6) 
Os(4.1) 
2300 
102 10.6 1.6 
26 NiFe Ta(2.8) 
Os(4.1) 
3500 
106 11.8 2.1 
__________________________________________________________________________ 
TABLE 2 
__________________________________________________________________________ 
GMR 
COMPOSITION (111) RATIO 
GMR 
MAIN PEAK OF SENSI- 
COMPO- INTEN- 
.rho. 
CHANGE 
TIVITY 
NENT M (at %) 
M' (at %) 
SITY 
(.mu..OMEGA.cm) 
(%) (%/Oe) 
__________________________________________________________________________ 
EXAMPLE 
__________________________________________________________________________ 
27 NiFe Nb(3.0) 
Si(6.2) 
4000 
112 11.7 2.6 
28 NiFe Mo(4.1) 
Si(6.2) 
3800 
115 11.5 2.4 
29 NiFe V(2.0) 
Si(6.2) 
2600 
118 10.4 2.2 
30 NiFe W(1.9) 
Si(6.2) 
2400 
104 10.5 1.6 
31 NiFe Ti(3.0) 
Si(6.2) 
2800 
103 10.4 2.7 
32 NiFe Zr(2.0) 
Si(6.2) 
3100 
107 10.9 1.9 
33 NiFe Hf(2.5) 
Si(6.2) 
2600 
102 10.7 2.4 
34 NiFe Ta(3.6) 
Si(6.2) 
2400 
100 10.5 2.1 
__________________________________________________________________________ 
COMATIVE EXAMPLE 
__________________________________________________________________________ 
1 NiFe -- -- 400 
30 2.5 0.6 
2 NiFe Nb(3.8) 
-- 650 
82 5.2 0.7 
3 NiFe Mo(4.8) 
-- 500 
75 4.2 0.5 
4 NiFe V(2.4) 
-- 620 
83 5.0 0.8 
5 NiFe W(1.8) 
-- 580 
78 4.8 0.6 
6 NiFe Ti(2.1) 
-- 610 
75 5.0 0.6 
7 NiFe Zr(1.5) 
-- 640 
85 5.2 0.7 
8 NiFe Hf(2.5) 
-- 600 
78 4.9 0.5 
9 NiFe Ta(3.6) 
-- 550 
80 4.5 0.5 
10 NiFe -- Cr(3.5) 
2000 
58 7.2 1.2 
11 NiFe -- Rh(5.0) 
1800 
56 7.0 1.1 
12 NiFe -- Os(4.1) 
2100 
61 6.8 0.9 
13 NiFe -- Si(6.2) 
1600 
55 7.1 1.0 
__________________________________________________________________________ 
It is clearly noted from Table 1 and Table 2 that the GMR of the working 
examples of this invention invariably led in the fcc (111) preferred 
orientation and exhibited high levels of magnetoresistance and, as a 
result, acquired perfect characteristics. In contrast, it is noted that 
the crystalline soft magnetic films incorporating an M element alone 
failed to acquire any improvement in the fcc (111) orientation property, 
though it attained an increase in magnetoresistance more or less but not 
fully satisfactorily. It is further noted that the crystalline soft 
magnetic films incorporating an M' element alone likewise failed to obtain 
a satisfactory increase in resistivity, though it was improved in the fcc 
(111) orientation property. As a result, the GMR heads of the comparative 
examples failed to acquire fully satisfactory characteristics. 
EXAMPLE 35 AND COMATIVE EXAMPLE 14 
On an Si substrate provided in advance thereon with a thermally oxidized 
film, a crystalline soft magnetic film of a composition of Ni.sub.75.1 
Fe.sub.18.2 Zr.sub.1.7 Rh.sub.5.0 obtained by the addition of Zr and Rh to 
a NiFe Permalloy was formed in a thickness of 30 nm. On this crystalline 
soft magnetic film as a soft magnetic bias film, a Ti film was superposed 
in a thickness of 40 nm as a nonmagnetic film and a NiFe alloy film in a 
thickness of 40 nm as an AMR film. Then, an AMR head was completed by 
superposing on the AMR film a pair of terminals made of Cu and adapted to 
feed a sense current. This AMR head had a specific structure identical to 
that of a conventional AMR head shown in FIG. 7. 
The AMR head according to the present working example showed a highly 
satisfactory ratio of change in magnetoresistance exceeding 3% (3.4%). 
When the conventional CoZr base film was used as a soft magnetic bias film 
(Comparative Example 14), the ratio of change in magnetoresistance shown 
by this film was about 1%. Since the resistivity of the CoZr base alloy is 
100 .mu..OMEGA.cm and is substantially equal to that of the NiFeZnRh soft 
magnetic film, it is safe to conclude that the difference in the ratio of 
change in magnetoresistance largely reflected the improvement of the AMR 
film in the fcc (111) orientation property. This fact demonstrates the 
usefulness of this invention. The results are shown in Table 3 and Table 
4. 
Examples 36 to 67 and Comparative Examples 15 to 26: 
AMR heads were manufactured by following the procedure of Example 35 while 
using crystalline soft magnetic films of varying compositions shown in 
Table 3 and Table 4 in the place of the crystalline soft magnetic film of 
Example 35. For comparison with this invention, AMR heads (Comparative 
Examples 15 to 22) using crystalline soft magnetic films resulting from 
the sole incorporation of an M element in the main component of a NiFe 
alloy and AMR heads (Comparative Examples 23 to 26) using crystalline soft 
magnetic films resulting from the sole incorporation of an M' element in 
the main component of a NiFe alloy were manufactured in the same manner as 
in Example 35. 
The AMR heads of the working examples of this invention and the comparative 
examples were tested for ratio of change in magnetoresistance. The results 
are shown in Table 3 and Table 4. 
TABLE 3 
______________________________________ 
COMPOSITION RATIO OF 
MEIN CHANG IN 
COMPO- MR 
NENT M(at %) M'(at %) 
(%) 
______________________________________ 
EXAMPLE 
______________________________________ 
35 NiFe Zr(1.7) Rh(5.0) 
3.4 
36 NiFe Nb(3.8) Cr(3.5) 
3.1 
37 NiFe Mo(4.8) Cr(3.5) 
3.2 
38 NiFe V(2.6) Cr(3.5) 
3.0 
39 NiFe W(1.7) Cr(3.5) 
2.8 
40 NiFe Ti(2.7) Cr(3.5) 
2.9 
41 NiFe Zr(1.9) Cr(3.5) 
3.4 
42 NiFe Hf(2.4) Cr(3.5) 
3.2 
43 NiFe Ta(3.2) Cr(3.5) 
3.1 
44 NiFe Nb(3.4) Rh(5.0) 
2.6 
45 NiFe Mo(4.6) Rh(5.0) 
2.5 
46 NiFe V(2.4) Rh(5.0) 
2.8 
47 NiFe W(1.8) Rh(5.0) 
2.9 
48 NiFe Ti(2.6) Rh(5.0) 
3.0 
49 NiFe Zr(1.7) Rh(5.0) 
3.4 
50 NiFe Hf(2.2) Rh(5.0) 
2.7 
51 NiFe Ta(3.4) Rh(5.0) 
3.5 
52 NiFe Nb(3.2) Os(4.1) 
3.4 
53 NiFe Mo(4.4) Os(4.1) 
2.6 
54 NiFe V(2.2) Os(4.1) 
2.8 
55 NiFe W(1.6) Os(4.1) 
2.4 
56 NiFe Ti(2.1) Os(4.1) 
2.3 
57 NiFe Zr(1.5) Os(4.1) 
2.9 
58 NiFe Hf(2.6) Os(4.1) 
3.5 
______________________________________ 
TABLE 4 
______________________________________ 
COMPOSITION RATIO OF 
MAIN CHANGE 
COMPO- IN MR 
NENT M(at %) M'(at %) 
(%) 
______________________________________ 
EXAMPLE 
______________________________________ 
59 NiFe Ta(2.8) Os(4.1) 
3.3 
60 NiFe Nb(3.0) Si(6.2) 
3.1 
61 NiFe Mo(4.1) Si(6.2) 
3.2 
62 NiFe V(2.0) Si(6.2) 
3.0 
63 NiFe W(1.9) Si(6.2) 
3.2 
64 NiFe Ti(3.0) Si(6.2) 
3.1 
65 NiFe Zr(2.0) Si(6.2) 
3.4 
66 NiFe Hf(2.5) Si(6.2) 
3.0 
67 NiFe Ta(3.6) Si(6.2) 
2.7 
______________________________________ 
COMATIVE EXAMPLE 
______________________________________ 
14 (CoZr) 1.0 
15 NiFe Nb(3.8) -- 1.5 
16 NiFe Mo(4.8) -- 1.2 
17 NiFe V(2.4) -- 1.4 
18 NiFe W(1.8) -- 1.3 
19 NiFe Ti(2.1) -- 1.0 
20 NiFe Zr(1.5) -- 1.1 
21 NiFe Hf(2.5) -- 0.9 
22 NiFe Ta(3.6) -- 0.8 
23 NiFe -- Cr(3.5) 
1.8 
24 NiFe -- Rh(5.0) 
1.7 
25 NiFe -- Os(4.1) 
1.9 
26 NiFe -- Si(6.2) 
1.6 
______________________________________ 
The ratios of change in magnetoresistance obtained in the examples were 
noted to be large as compared with those obtained in the comparative 
examples. It is concluded that the increases in the ratio of change in MR 
resulted from the exaltations of the fcc (111) preferred orientation of 
the AMR film due to the use of the crystalline soft magnetic films 
similarly to the results obtained in Example 35. 
Example 68: 
On an Si substrate provided in advance thereon with a thermally oxidized 
film, a crystalline soft magnetic film of a composition of Ni.sub.73.7 
Fe.sub.19.0 Nb.sub.3.8 Cr.sub.3.5 was formed in a thickness of 10 nm 
through the medium of a nonmagnetic metal film of Ti formed in a thickness 
of 5 nm as an undercoat. Then, a spin valve film and an antiferromagnetic 
exchange bias film were superposed thereon in the same manner as in 
Example 1. 
The GMR film of Example 68 thus obtained was tested for fcc (111) 
orientation property. As a result, it was confirmed that the peak showing 
the fcc (111) intensity was 12000, a value about five times that of a GMR 
head which omitted the interposition of a nonmagnetic undercoating film. 
This improvement is logically explained by a supposition that the 
nonmagnetic metal film made of Ti aided in the growth of the crystalline 
soft magnetic film and, as a result, allowed this film to be crystallized 
in spite of such a small thickness as 10 nm and brought out an increase in 
the orientation property of the GMR film. Thus, the ratio of change in GMR 
was 12.4% and the sensitivity of GMR was 2.4%/Oe, i.e. magnitudes higher 
than those obtained in Example 1. 
The relation between the thickness and the ratio of change in 
magnetoresistance (ratio of change in GMR) obtained of the crystalline 
soft magnetic film provided with a nonmagnetic undercoating film of Ti is 
shown in FIG. 5. This diagram, as compared with that of FIG. 3, clearly 
shows that a high ratio of change in GMR was obtained particularly when 
the film thickness was small. 
The head of this working example may use a structure shown in FIG. 8 
instead. This structure, however, has the possibility of cut off of the 
exchange coupling between the ferromagnetic bias film 12 and the magnetic 
undercoating film 11 by the nonmagnetic undercoating film. Preferably, 
therefore, the nonmagnetic undercoating film 13 is disposed underneath the 
ferromagnetic bias film 12 as shown in FIG. 9. 
EXAMPLES 69 TO 99 
GMR heads were manufactured by following the procedure of Example 68 while 
using crystalline soft magnetic films of varying compositions shown in 
Table 5 and Table 6 in the place of the crystalline soft magnetic film of 
Example 68. The crystalline soft magnetic films in the GMR heads of these 
working examples were tested for (111) peak intensity and, at the same 
time, the GMR heads were tested for ratio of change in GMR and GMR 
sensitivity. The results are additionally shown in Table 5 and Table 6. 
TABLE 5 
______________________________________ 
GMR 
COMPOSITION (111) RATIO GMR 
MAIN PEAK OF SENSI- 
COMPO- INTEN- 
CHANGE TIVITY 
NENT M (at %) M' (at %) 
SITY (%) (%/Oe) 
______________________________________ 
EXAMPLE 
______________________________________ 
68 NiFe Nb(3.8) Cr(3.5) 
12000 12.4 2.4 
69 NiFe Mo(4.8) Cr(3.5) 
12500 12.6 2.2 
70 NiFe V(2.6) Cr(3.5) 
11500 13.2 2.6 
71 NiFe W(1.7) Cr(3.5) 
12000 11.8 1.9 
72 NiFe Ti(2.7) Cr(3.5) 
14400 12.2 2.0 
73 NiFe Zr(1.9) Cr(3.5) 
16300 12.7 2.8 
74 NiFe Hf(2.4) Cr(3.5) 
12500 13.1 2.2 
75 NiFe Ta(3.2) Cr(3.5) 
10100 13.3 1.8 
76 NiFe Nb(3.4) Rh(5.0) 
11500 12.1 3.1 
77 NiFe Mo(4.6) Rh(5.0) 
16300 11.4 1.3 
78 NiFe V(2.4) Rh(5.0) 
13400 11.8 1.4 
79 NiFe W(1.8) Rh(5.0) 
15400 12.2 1.9 
80 NiFe Ti(2.6) Rh(5.0) 
12500 13.6 2.0 
81 NiFe Zr(1.7) Rh(5.0) 
13900 12.5 1.6 
82 NiFe Hf(2.2) Rh(5.0) 
14900 12.7 2.4 
83 NiFe Ta(3.4) Rh(5.0) 
12500 12.2 2.4 
84 NiFe Nb(3.2) Os(4.1) 
13000 12.1 2.9 
85 NiFe Mo(4.4) Os(4.1) 
13400 13.1 2.8 
86 NiFe V(2.2) Os(4.1) 
11500 12.8 2.4 
87 NiFe W(1.6) Os(4.1) 
12500 11.5 2.2 
88 NiFe Ti(2.1) Os(4.1) 
12000 12.5 1.7 
89 NiFe Zr(1.5) Os(4.1) 
11500 12.2 2.0 
90 NiFe Hf(2.6) Os(4.1) 
11000 12.7 1.9 
91 NiFe Ta(2.8) Os(4.1) 
16800 14.2 2.5 
______________________________________ 
TABLE 6 
______________________________________ 
GMR 
COMPOSITION (111) RATIO GMR 
MAIN PEAK OF SENSI- 
COMPO- INTEN- 
CHANGE TIVITY 
NENT M (at %) M' (at %) 
SITY (%) (%/Oe) 
______________________________________ 
EXAMPLE 
______________________________________ 
92 NiFe Nb(3.0) Si(6.2) 
19200 14.0 3.1 
93 NiFe Mo(4.1) Si(6.2) 
18200 13.8 2.9 
94 NiFe V(2.0) Si(6.2) 
12500 12.5 2.6 
95 NiFe W(1.9) Si(6.2) 
11500 12.6 1.9 
96 NiFe Ti(3.0) Si(6.2) 
13400 12.5 3.2 
97 NiFe Zr(2.0) Si(6.2) 
14900 13.1 2.3 
98 NiFe Hf(2.5) Si(6.2) 
12500 12.8 2.9 
99 NiFe Ta(3.6) Si(6.2) 
11500 12.6 2.5 
______________________________________ 
It is noted from these results that the intensities of fcc (111) peak 
obtained of the samples of the working examples were nearly five times 
those obtained of the samples of the comparative examples 1 to 13. It is 
further remarked that the samples of the working examples were improved in 
ratio of magnetoresistive change and in GMR sensitivity as well. 
Separately, GMR heads were manufactured by using Ta, Zr, Cr, Nb, and Hf in 
the place of Ti as the undercoats for the relevant crystalline soft 
magnetic films. It was confirmed that they showed larger intensities of 
fcc (111) peak about three to five times than those of the samples in the 
comparative examples. 
The magnetoresistive head of the present invention enjoys improvement in 
such characteristics as ratio of change in magnetoresistance because it 
has a crystalline soft magnetic film with large resistivity and capable of 
enhancing the preferred orientation disposed as an undercoat for a 
magnetoresistive film as described above.