HIGH STABILITY TRANSITION METAL NZP TYPE PHOSPHATES

Abstract: Transition metal NZP type compounds are synthesized. Examples of these compounds include MnZr4(PO4)6, FeZr4(PO4)6, CoZr4(PO4)6, NiZr4(PO4)6, and CuZr4(PO4)6. These compounds are synthesized by the Xerogel process. These transition metal NZP type compounds can be used as colorants in applications such as ceramic glazes where high thermal stability of the colorant is important.

Description: TITLE OF THE INVENTION High Stability Transition Metal NZP Type Phosphates TECHNICAL FIELD The invention relates to high thermal stability zirconium phosphates, having the NZP structure. More particularly, the invention relates to transition metal, zirconium phosphates having high thermal stability. BACKGROUND ART The term NZP refers to NaZr 2 (P0 ) 3 , as well as to related isostructural phosphates and silicophosphates having a similar crystal structure. The NZP crystal structure is basically a three-dimensional network of P0 4 tetrahedra and Zr0 6 octahedra which are linked together by shared oxygens. Each zirconium atom is located on a three-fold axis parallel to the c-axis, and is coordinated to six oxygens. Each phosphorous atom is located on a two-fold axis parallel to the a-axis, and is coordinated to 4 oxygens. Thus each ZrOβ octahedron is connected to six P0 tetrahedra through the six oxygen atoms making up the corners of the Zr0 6 octahedron. Sodium ions are located at the interstitial sites created by the framework, but are replaced with other ions depending on the NZP analog. The NZP structure is exceptionally flexible towards ionic substitution at various lattice sites. The stoichiometry of NZP compounds can be generalized by the formula A 0 _ B (X0 4 ) 3 , wherein A represents a relatively large monovalent or divalent cation, B designates a medium- sized (octahedrally-coordinated) trivalent, tetravalent, or pentavalent cation, and X denotes a small ( tetrahedrally- coordinated) tetravalent, pentavalent, or hexavalent cation. NZP stoichiometry requires the cation ratio B:X to be approximately 2:3. The number of A atoms can range from 0-4, depending upon the net charge of the B and X cations. A wide variety of NZP type compounds have been prepared. NZP type compounds have been reported for alkali metal and alkaline earth metal cations substituted into the sodium site of the NZP structure. Compounds in which substitutions in the Zr sites, and in the P sites, as well as coupled substitutions involving two or all three of these sites, also have been reported. Various ceramic compounds have been employed as colorants in ceramic compositions such as glazes. A well known ceramic compound that has been used as a colorant is Zircon. Zircon, however, is expensive. Although Zircon has been widely accepted as a ceramic colorant, a need continues to exist for cost-effective, high thermal stability compounds which can impart desired color characteristics to the ceramic composition during firing. DISCLOSURE OF THE INVENTION The invention relates to novel transition metal NZP compounds and diphasic mixtures thereof . These compounds exhibit very high thermal stability and retain their intrinsic color when employed in a ceramic composition. In a first aspect, inventive compositions have the general formula M x ZrP 6 0 24 , where M is any of Mn, Fe, Co, Ni , or Cu, and x is about 0.1 to 1.2, preferably about 0.9 to about 1.0. In another aspect, The inventive compositions have the general formula (Nι_ x M x )ZrP 6 0 24 , where M and N are different and each is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to 1.0, preferably about 0.8 to about 1.0. The compounds of the invention, due in part to their extremely high thermal stability when for example, employed as additives in ceramic compositions such as glasses and glaze compositions, impart their intrinsic color to the ceramic compositions . DESCRIPTION OF THE PREFERRED EMBODIMENTS Materials The starting materials used to synthesize the NZP compounds of the invention preferably are chemically pure. However, minor amounts of impurities which do not cause a significantly large amount, i.e. greater than about 3.0% by volume, of any second phase to occur in the compound may be tolerated. Starting materials which may be used to synthesize the NZP compounds include water soluble salts of zirconium such as zirconium oxychloride and zirconium nitrate, preferably zirconium oxychloride; metal chlorides and metal nitrates where the metal cation is a transition metal cation such as Cu, Fe, Ni , Mn, and Co, for substitution into the N site of the NZP compound; and phosphate compounds such as ammonium dihydrogen phosphate, phosphoric acid, and diammonium hydrogen, preferably phosphoric acid. Silicon can be partially substituted for phosphorous, and any deficient charge can be compensated by the transition metal in the N site. Useful sources of silicon include SiCl , Si0 2 , tetraethoxysilane, and tetramethoxysilane, preferably tetraethoxysilane . Synthesis The NZP compounds of the invention are made from precursors of the compounds . The precursors may be made by various known ceramic processing methods such as solid state reaction and Xerogel . Preferably, the precursors are made by the Xerogel method. Where the Xerogel method is employed to manufacture the precursors for the NZP compounds any of aqueous metal chlorides, metal nitrates, or mixtures thereof, preferably aqueous metal chlorides, more preferably aqueous metal chlorides having a concentration of about 0.1M to about 2.0M, most preferably about 1.0M to about 2.0M, are combined with rr tr 0 cn φ o o 3 "9 0 ω H- rt H- o P cn . Examples 1-4: Cu-Zr-P NZP Type Compounds Example 1 : CuZr ( P0 4 ) 6 10 ml of aqueous 1.0 M CuCl 2 is dissolved in 80 ml aqueous 0.5M ZrOCl 2 . The resulting mixture is titrated by dropwise addition of 60 ml of 1.0M H 3 P0 4 under constant stirring at 20-50 RPM. Addition of the 1.0M H 3 P0 causes immediate formation of a gel. The gel continues to form until all of the H 3 P0 is added. The gel is dried at 70°C for 24 hours and then at 150°C for 4 hours. The resulting dried gel is compressed under 200 MPa into a circular pellet measuring 1 cm in diameter. The pellet is fired in air at 900 °C for 16 hours. During firing, the temperature is increased at the rate of 5°C/min. until the temperature reaches 900 °C. The temperature is maintained at 900 °C for 16 hours, and then cooled to room temperature. The resulting CuZr 4 (P0 ) 6 has a light yellowish green color. Example 2: Cu 0 . 8 z r (P0 4 ) 6 10 ml aqueous 0.8 M CuCl 2 is dissolved in 80 mis aqueous 0.5M ZrOCl 2 . The resulting mixture is titrated by dropwise addition of 60 is of 1.0M H 3 P0 4 under constant stirring at 20- 50 RPM. Any gel which forms is dried at 70°C for 24 hours and then at 150°C for 4 hours. The dried gel powder is fired under flowing Ar gas. During firing, the temperature of the furnace is increased at a rate of 5°C/min. until the temperature reaches 900°C. The gel is maintained at 900°C for 16 hours, and then cooled to room temperature . Example 3: Cuι.ιZr (P0 ) 6 The procedure of example 2 is repeated except that aqueous 1.1 M CuCl 2 is substituted for 0.8 M CuCl 2 . Example 4: Cuι .2 Zr 4 (P0 ) 6 The procedure of example 2 is repeated except that aqueous 1.2 M CuCl 2 is substituted for 0.8 M CuCl 2 . Examples 5-8: Co-Zr-P NZP type compounds Example 5: CoZr 4 (P0 4 ) 6 10 mis of aqueous l.O M CoCl 2 is dissolved in 80 is aqueous 0.5M ZrOCl . The resulting mixture is titrated by dropwise addition of 60 mis of l.OM H 3 P0 4 under constant stirring at 20-50 RPM. The l.OM H 3 P0 causes immediate formation of a gel. The gel continues to form until all of the H 3 P0 4 is added. The gel is dried at 70°C for 24 hours and then at 150°C for 4 hours. The resulting dried powder is placed into a silica tube. The tube having the powder therein is evacuated, sealed and fired at 900°C for 16 hours. During firing, the temperature is increased at a rate of 5°C/min. until the temperature reaches 900°C. The temperature is maintained at 900°C for 16 hours, and then cooled to room temperature. Example 6: Co 0 .8Zr 4 (P0 4 ) 6 The procedure of example 5 is employed except that 0.8 M CoCl 2 is substituted for l.O M CoCl 2 . Example 7: Co x .ιZr 4 (P0 ) 6 The procedure of example 5 is employed except that 1.1 M CoCl 2 is substituted for 1.0 M CoCl 2 . Example 8: Cθι. 2 Zr (P0 4 ) 6 10 ml 1.2 M CoCl 2 is dissolved in 80 mis aqueous 0.5M ZrOCl 2 . The resulting mixture is titrated by dropwise addition of 60 mis of l.OM H 3 P0 4 under constant stirring at 20-50 RPM. The l.OM H 3 P0 causes immediate formation of a gel. The gel continues to form until all of the H 3 P0 is added. The gel is dried at 70°C for 24 hours and then at 150°C for 4 hours. The resulting dried powder is placed into a silica tube. The tube having the powder therein is evacuated, sealed and fired at 900°C for 16 hours. During firing, the temperature is increased at a rate of 5°C/min. until the temperature reaches 900°C. The temperature is maintained at 900°C for 16 hours, and then cooled to room temperature. The resulting CoZr (P0 ) 6 has a deep violet color. Example 8A: Cθι. 2 Zr (P0 4 ) ,, The procedure of example 8 is followed except that the resulting dried powder is fired in air. Examples 9-12: Ni-Zr-P NZP type compounds Example 9: NiZr 4 (P0 4 ) 6 10 mis of aqueous l.O M NiCl 2 is dissolved in 80 mis aqueous 0.5M ZrOCl 2 . The resulting mixture is titrated by dropwise addition of 60 mis of l.OM H 3 P0 4 under constant stirring at 20-50 RPM. Any gel that forms is dried at 70°C for 24 hours and then at 150°C for 4 hours. The dried gel powder is placed into evacuated and sealed silica tubes, and fired. During firing, the temperature of the furnace is increased at a rate of 5 °C/min. until the temperature reaches 16°C. The gel is maintained at 900 °C for 16 hours, and then cooled to room temperature. Example 10: Ni 0 .βZr 4 (P0) 6 The procedure of example 9 is employed except that 0.8 M NiCl 2 is substituted for l.O M NiCl 2 . Example 11: Niι.ιZr 4 (P0 ) 6 The procedure of example 9 is employed except that 1.1 M NiCl 2 is substituted for l.O M NiCl 2 . Example 12: Ni_.. 2 Zr (P0 4 ) 6 The procedure of example 9 is employed except that 1.2 M NiCl 2 is substituted for l.O M NiCl 2 . The resulting Niι. 2 Zr 4 (P0 4 ) 6 is orange. Example 12A: NiZr 4 (P0 ) 6 The procedure of example 9 is followed except that the resulting dried powder is fired in air. Examples 13-16: Fe-Zr-P NZP type compounds Example 13: FeZr (P0 ) 6 10 mis of aqueous 1.0 M FeCl 2 is dissolved in 80 is aqueous 0.5M ZrOCl 2 . The resulting mixture is titrated by dropwise addition of 60 mis of l.OM H 3 P0 4 under constant stirring at 20-50 RPM. The l.OM H 3 P0 causes immediate formation of a gel. The gel continues to form until all of the H 3 P0 4 is added. The gel is dried at 70°C for 24 hours and then at 150°C for 4 hours. The dried gel powder is fired under flowing Ar. During firing, the temperature of the furnace is increased at 5°C/min. until the temperature reaches 900°C. The gel is maintained at 900°C for 16 hours, and then cooled to room temperature. The resulting FeZr (P0 ) 6 is tan in color. Example 14: Fe 0 .sZr (P0 ) 6 The procedure of example 13 is followed except that 0.8 M FeCl 2 is substituted for 1.0 M FeCl 2 . Example 15: Fβι.ιZr (P0 ) 6 The procedure of example 13 is followed except that 1.1 M FeCl 2 is substituted for 1.0 M FeCl 2 . Example 16: Feι. 2 Zr 4 (P0 4 ) 6 The procedure of example 13 is followed except that 1.2 M FeCl 2 is substituted for the 1.0 M FeCl 2 . Example 16A: FeZr (P0 ) 6 The procedure of example 13 is followed except that the resulting dried powder is fired in nitrogen. Examples 17-20: Mn-Zr-P NZP type compounds Example 17: MnZr 4 (P0 4 ) 6 10 mis of aqueous l.OM MnCl 2 is dissolved in 80 mis aqueous 0.5M ZrOCl 2 . The resulting mixture is titrated by dropwise addition of 60 mis of l.OM H 3 P0 under constant stirring at 20-50 RPM. Any gel which forms is dried at 70°C for 24 hours and then at 150°C for 4 hours. The dried gel powder is fired under flowing Ar gas. During firing, the temperature of the furnace is increased at a rate of 5°C/min. until the temperature reaches 900°C. The gel is maintained at 900°C for 16 hours, and then cooled to room temperature . Example 18: Mn 0 .gZr 4 (P0) 6 The procedure of example 17 is followed except that 0.8 M MnCl 2 is substituted for l.O M MnCl 2 . Example 19: Mnχ.ιZr 4 (P0 ) 6 The procedure of example 17 is followed except that 1.1 M MnCl 2 is substituted for l.O M MnCl 2 . Example 20: Mn x . 2 Zr 4 (P0 ) 6 The procedure of example 17 is followed except that 1.1 M MnCl 2 is substituted for l.O M MnCl 2 . The resulting Mnι. 2 Zr (P0 4 ) 6 s faintly pink-white colored without extraneous X-ray diffraction lines as measured on a SCINTAG PAD-V diffractometer using Cu K-alpha radiation. Example 20A: MnZr 4 (P0)δ The procedure of example 17 is repeated except that the powder is fired in nitrogen. Examples 21-23: Mixed transition metal-Zr-P NZP type compounds Example 21: Co 0 . 5 Nio.5Zr 4 (P0 4 ) 6 5 mis of aqueous l.OM CoCl 2 and 5 mis of aqueous l.OM NiCl 2 are blended to form a mixed metal cation solution. This solution is dissolved in 80 mis aqueous 0.5M ZrOCl 2 . The resulting mixture is titrated by dropwise addition of 60 mis of l.OM H 3 P0 4 under constant stirring at 20-50 RPM. The gel which forms is dried at 70°C for 24 hours and then at 150°C for 4 hours . The dried gel powder is fired under flowing Ar gas. During firing, the temperature of the furnace is increased at a rate of 5°C/min. until the temperature reaches 900°C. The gel is maintained at 900°C for 16 hours, and then cooled to room temperature . Example 22: Cu 0 .5Ni 0 .5Zr (P0 ) 6 The procedure of example 21 is employed except that l.OM CuCl 2 is substituted for the l.OM CoCl 2 . Example 23: Cr 0 . 333 Co 0 .5Zr 4 (P0 4 ) 6 The procedure of example 21 is employed except that 0.66M CrCl 3 is substituted for the l.OM NiCl 2 . Example 23A: The procedure of example 23 is followed except that the loose powder is fired in air. In another aspect of the invention, the transition metal NZP type compounds corresponding to any of M x ZrP 6 θ , where M is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to about 1.2, or (Nι_ x M x )Zr 4 P 6 0 24 where M and N are different and each is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to 1.0 are employed to produce modified ceramic compositions such as modified ceramic glaze compositions, modified glass compositions and filled organic polymeric compositions to impart color. Examples of modified ceramic glaze compositions include a ceramic glaze in an amount of about 80% to about 95%, preferably about 90%, optional opacifier in an amount of up to about 14%, preferably about 6%, and a transition metal NZP compound of the invention in an amount of about 2% to about 8%, preferably about 4% all amounts based on the total weight of the modified glaze composition. Examples of modified glass compositions include a glass in an amount of about 90% to about 98%, preferably about 95%, and a transition metal NZP of the invention in an amount of about 2% to about 98%, preferably about 5%, all amounts based on the total weight of the modified glass. Examples of orgaric polymers include homopolymers and copolymers of such as polyethylene and polypropylene. The polymer may be present in an amount of about 95-98%, preferably 97%, and the transition metal compound may be present in an amount of about 5-2%, preferably about 3%, all amounts based on the combined weight of polymer and transition metal compounds . This aspect of the invention is illustrated below by the following nonlimiting examples. Example 24: Modified ceramic glaze composition A modified ceramic glaze is prepared by mixing a ceramic glaze composition with an opacifier and a transition metal NZP compound of the invention. The ceramic glaze composition includes 0-5% Li 2 0, 0-5% Na 2 0, less than 2% by weight K 2 0, 0-3% MgO, 0-4% CaO, 0-4% SrO, 0-4% BaO, 0-4% ZnO, 15-27% B 2 0 3 10- 20% A1 2 0 3 , 43-58% Si02 , 0-3% Ti0 2 , 0-4% Zr0 2 , 0-2% Sb 2 0 3 , and 0-3% F, the opacifier is Zirconium Silicate, and the transition metal NZP compound is Mnι. 2 Zr (P0 ) 6 . All amounts are in percent by weight based on the total combined weight of glaze, Zirconium Silicate, and Mnι. 2 Zr (P0 4 ) 6 : Component Amount (%) Glaze 90 Zirconium Silicate 6 Example 25: Filled Polymer A filled polymer is prepared by mixing a polymer and a transition metal NZP compound of the invention. The polymer is polyethylene and the transition metal NZP compound is Mnχ. 2 Zr (P0 ) 6 • All amounts are in percent by weight based on the total combined weight of polymer and Mnι. 2 Zr (P0 4 ) 6 = Component Amount (%) Polyethylene 95 Mn 1 . 2 Zr 4 (P0 4 ) 6 _5 Total: 100 Example 26: Modified glass composition A modified glass composition is prepared by mixing a silicate glass composition and a transition metal NZP compound of the invention. The silicate glass composition is PbO--ZnO- B 2 0 3 , and the transition metal NZP compound is Mnι. 2 Zr 4 (P0 4 ) 6 • All amounts are in percent by weight based on the total combined weight of the glass and Mnι. 2 Zr 4 (P0 ) 6 : Component Amount (%) Silicate Glass 90 Mnι. 2 Zr 4 (P0 4 ) 6 _5 Total: 100

Claims: Claims : 1. A high thermal stability, transition metal NZP type compound having a formula M x Zr 4 P 6 θ 2 , where M is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to about 1.2. 2. The compound of claim 1 wherein x is about 0.8 to about 1.2. 3. The compound of claim 1 wherein M is Cu and x is 1.0 4. The compound of claim 1 wherein M is Ni and x is 1.2. 5. The compound of claim 1 wherein M is Fe and x is 1.0. 6. The compound of claim 1 wherein M is Mn and x is 1.2. 7. A high thermal stability, transition metal NZP type compound having a formula (Nι_. x M x )Zr 4 P 6 0 2 , where M and N are different and each is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to 1.0. 8. The compound of claim 7 wherein x is about 0.8 to about 1.0. 9. The compound of claim 7 wherein N is Co, M is Ni and x is 0.5. 10. The compound of claim 1 wherein P is partially substituted by Si. 11. The compound of claim 7 wherein P is partially substituted by Si. 12. A modified glaze composition comprising a ceramic glaze composition and a transition metal NZP compound corresponding to any of M_Zr 4 P 6 0 4 , where M is any of Mn, Fe, Co, Ni , or Cu, and x is about 0.1 to about 1.2, or (Nι_ x M x )ZrP 6 0 24 where M and N are different and each is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to 1.0. 13. The modified glaze composition of claim 12 wherein the modified ceramic glaze composition includes a ceramic glaze in an amount of about 80% to about 95%, and the transition metal NZP compound in an amount of about 2% to about 8%, all amounts based on the total weight of the modified glaze composition. 14. The modified glaze composition of claim 13 wherein the ceramic glaze is present in an amount of about 90%. 15. The modified glaze composition of claim 14 wherein the opacifier is present in an amount of up to about 14%. 16. The modified glaze composition of claim 13 wherein the opacifier is present in an amount of up to about 6%. 17. The modified glaze composition of claim 16 wherein the transition metal NZP compound is present in an amount of about 4%. 18. The modified glaze composition of claim 12 wherein the glaze composition comprises 0-5% Li 2 0, 0-5% Na 2 0, less than 2% by weight K 2 0, 0-3% MgO, 0-4% CaO, 0-4% SrO, 0-4% BaO, 0-4% ZnO, 15-27% B 2 0 3 , 10-20% Al 2 0 3 , 43-58% Si02 , 0-3% Ti0 2 , 0-4% Zr0 2 , 0-2% Sb 2 0 3 , and 0-3% F, the opacifier is Zirconium Silicate, and the transition metal NZP compound is Mnι. 2 Zr 4 (P0 4 ) 6 . 19. A method of manufacture of a transition metal NZP compound corresponding to any of M x ZrP 6 0 24 , where M is any of Mn, Fe, Co, Ni , or Cu, and x is about 0.1 to about 1.2, or (Nι- X M x ) Zr 4 P 6 0 2 where M and N are different and each is any of Mn, Fe, Co, Ni , or Cu, and x is about 0.1 to 1.0 comprising, mixing a transition metal cation solution selected from the group consisting of aqueous metal chlorides, metal nitrates, or mixtures thereof with a zirconium cation solution selected from the group consisting of zirconium oxychloride, zirconium nitrate, and zirconium dioxide, to form a mixed transition metal cation solution, reacting the mixed transition metal cation solution with an aqueous phosphate selected from the group consisting of ammonium dihydrogen phosphate, phosphoric acid, and diammonium hydrogen, preferably phosphoric acid solutions having a concentration of about 0.2M to about 6.0M, preferably about 3.0M to about 6.0M to precipitate a gel, drying the gel to produce a powder, and firing the powder to produce a transition metal NZP compound. 20. The method of claim 19 wherein the transition metal cation solution is an aqueous transition metal chloride. 21. The method of claim 20 wherein the zirconium cation solution is zirconium oxychloride. 22. The method of claim 21 wherein the aqueous phosphate is phosphoric acid. [received by the International Bureau on 26 June 2001 (26.06.01); original claims 1, 7, 8 and 19 amended; new claims 23 and 24 added; remaining claims unchanged (3 pages)] 1. A high thermal stability, transition metal NZP type compound having a formula M x Zr 4 P r .O j!4 , where M is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to about 1.2. 2. The compound of claim 1 wherein x is about 0.8 to about 1.2. 3. The compound of claim 1 wherein M is Cu and x is 1.0 4. The compound of claim 1 wherein M is Ni and x is 1.2. 5. The compound of claim 1 wherein M is Fe and x is 1.0. 6. The compound of claim 1 wherein M is Mn and x is 1.2. 7. A high thermal stability, transition metal NZP type compound having a formula (Nι_ x M x ) Zt ? 6 0 2 ^ , where M and N are different and each is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to 1.0. 8. The compound of claim 7 wherein x is about 0.8 to about 1.0- 9. The compound of claim 7 wherein N is Co, M is Ni and x is 0.5. 10. The compound of claim 1 wherein P is partially substituted by Si. 11. The compound of claim 7 wherein P is partially substituted by Si. 12. A modified glaze composition comprising a ceramic glaze composition and a transition metal NZP compound corresponding to any of M x Zr 4 P t ,0 24/ where M is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to about 1.2, or (N,. x M κ )Zr 1 P 6 0 2l where M and N are different and each is h any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to 1.0. 13. The modified glaze composition of claim 12 wherein the modified ceramic glaze composition includes a ceramic gla2e in an amount of about 80% to about 95%, and the transition metal 0 NZP compound in an amount of about 2% to about 8%, all amounts based on the total weight of the modified glaze composition. 14. The modified glaze composition of claim 13 wherein the ceramic qlaze is present in an amount of about 90%. 5 15. The modified glaze composition of claim 14 wherein the opacifier is present in an amount of up to about 14%. 16. The modified glaze composition of claim 13 wherein the 0 opacifier is present in an amount of up to about 6%. 17. The modified glaze composition of claim 16 wherein the transition metal NZP compound is present in an amount of about 4%. 5 18. The modified glaze composition of claim 12 wherein the glaze composition comprises 0-5% Li 2 0, 0-5% Na 2 0, less than 2% by weight .O, 0-3% MgO, 0-4% CaO, 0-4% SrO, 0-4% BaO, 0-4% ZnO, 15-27% B 2 0 3 , 10-20% A1 2 0 3 , 43-58% Si02, 0-3% Ti0 2 , 0-4% 0 Zr0 7, , 0-2% Sb 2 0- 3 , and 0-3% F, the opacifier is Zirconium Silicate, and the transition metal NZP compound is Mn 1 . 2 Zr 4 (P0 4 ) 6 . 19. A method of manufacture of a transition metal NZP compound 35 corresponding to any of M„Zr « P 6 0 24 , where M is any of Mn, Fe, Co, Ni, or Cu, and x is about 0.1 to about 1.2, or (M,_ x M Zr 4 P Λ 0 ?4 where M and N are different and each is a ny of Mn, Fe, Co, Ni, o Cu, and x ia about 0.1 to 1.0 comprising, mixing a transition metal cation solution selected from the group consisting of aqueous metal chlorides, metal nitrates, or mixtures thereof with a zirconium cation solution selected from the group consisting of zirconium oxychloride, zirconium nitrate, and zirconium dioxide, to form a mixed transition metal cation solution, reacting the mixed transition metal cation solution wi h an aqueous phosphate selected from the group consisting of ammonium dihydrogen phosphate, phosphoric acid, and diammonium hydrogen phosphate to precipitate a gel, drying the gel to produce a powder, and firing the powder to produce a transition metal NZP compound corresponding to the formula M x Zr,,P 6 Q 24 . 20. The method of claim 19 wherein the transition metal cation solution is an aqueous transition metal chloride. 21. The method of claim 20 wherein the zirconium cation solution is zirconium oxychloride. 22. The method of claim 21 wherein the aqueous phosphate is phosphoric acid. 23. The method of claim 19 wherein the aqueous phosphate is phosphoric acid having a concentration of about 0.2M to about 6.0M. 24. The method of claim 19 wherein the aqueous phosphate is phosphoric acid having a concentration of about 3.0M to about 6.0M. STATEMENT UMDER ARTICLE 19 11) In accordance with Article 19 and Rule 46 of the Regulations under the Patent Cooperation treaty, Applicant in the above- identified International Application hereby amends the specification and claims of the above-identified application as 3tated above. Claims 2-6, 9-18 and 20-22 remain unchanged. Enclosed are replacement sheet3 13-15 which contain new claims 1, 7, 8, 19 as well s.s claims 23 and 24 identified above. Replacement pages 13-15 should be substituted for original pages 13-15. Enclosed are replacement sheets 3 a d 6-10 of the specification. Replacement sheets 3 and 6-10 should be substituted for original sheets 3 and 6-10. The amendments to the specification as presented in new sheets 3 and 6-10 corrects grammatical errors. The amendments to original claims 1, 7, 8 and 1.9 as presented in new claims 1. 7, 8 and 19 clarifies Applicant's claimed invention.

Inventors: GOULD WILLIAM W, KOMARNENI SRIDHAR, GOULD, WILLIAM, W., KOMARNENI, SRIDHAR
Applicants: PENN STATE RES FOUND, THE PENN STATE RESEARCH FOUNDATION
Application year: 2001
Main classification: C03C8
IPC codes: C01B25, C03C8