Lead zirconate-titanate powder of particle sizes between 0.02 and 0.2 micron, process for producing same, and high-density piezoelectric ceramics made of powder

Claim 2

A process for producing crystalline powder of a composition given by the chemical formula: Pb Ti q Zr p O 3 , where y and z represent mol ratios, the sum of q and p being equal to 1.00, the mol ratio q being not smaller than 0.45 and not greater than 0.90, the mol ratio p being not smaller than 0.10 and not greater than 0.55, comprising the steps of: preparing an acidic aqueous solution of the metallic elements in the mol ratios given in said formula, neutralizing said aqueous solution to provide a suspension of hydroxides of the metallic elements, subjecting said suspension in an autoclave under pressure to a temperature between 150° and 300°C for a time sufficient to produce crystalline precipitate of said composition and of an average particle size between 0.02 and 0.2 micron in a mother liquor, and separating said precipitate from said mother liquor.

Claim 3

A process for preparing a composition represented by the chemical formula: Pb(Mn 1/3 .Sb 2/3 ) x .Ti y .Zr z .O 3 , where x, y and z represent mol ratios, the sum of x, y and z being equal to 1.00, and x, y, and z fall on the boundary of and within a heptagon ABCDEFG in a triangular compositional diagram of a ternary-system solid solution shown in FIG. 1, the vertices A, B, C, D, E, F, and G of said heptagon being given by: x y z ______________________________________ A 0.10 0.80 0.10 B 0.01 0.71 0.28 C 0.01 0.09 0.90 D 0.05 0.05 0.90 E 0.30 0.05 0.65 F 0.30 0.50 0.20 G 0.20 0.70 0.10, ______________________________________ said process comprising the steps of: preparing an aqueous solution of the metallic elements in the mol ratios given in said formula, neutralizing said aqueous solution to provide a suspension of hydroxides of said metallic elements, subjecting said suspension in an autoclave under pressure to a temperature between 150° and 300°C for a time sufficient to produce crystalline precipitate of said composition and of an average particle size between 0.02 and 0.2 micron in a mother liquor, and separating said precipitate from said mother liquor.

Claim 4

A process for preparing a composition represented by the chemical formula: Pb(Mn 1/3 .Sb 2/3 ) x .Ti y .Zr z .O 3 , where x, y and z represent mol ratios, the sum of x, y and z being equal to 1.00, and x, y, and z fall on the boundary of and within a heptagon ABCDEFG in a triangular compositional diagram of a ternary-system solid solution shown in FIG. 1, the vertices A, B, C, D, E, F, and G of said heptagon being given by: x y z ______________________________________ A 0.10 0.80 0.10 B 0.01 0.71 0.28 C 0.01 0.09 0.90 D 0.05 0.05 0.90 E 0.30 0.05 0.65 F 0.30 0.50 0.20 G 0.20 0.70 0.10, ______________________________________ said process comprising the steps of: preparing an aqueous solution of the metallic elements in the mol ratios given in said formula, neutralizing said aqueous solution to provide a suspension of hydroxides of said metallic elements, subjecting said suspension in an autoclave under pressure to a temperature between 150° and 300°C for a time sufficient to produce crystalline precipitate of said composition and of an average particle size between 0.02 and 0.2 micron in a mother liquor, and separating said precipitate from said mother liquor.

Claim 5

A process for preparing a composition represented by the formula: Pb(Mn 1/3 .Nb.sub. 2/3) x .Ii.sub. y.Zr.sub. z.O.sub. 3, where x, y and z represent mol ratios, the sum of x, y, and z being equal to 1.00, and x, y and z fall on the boundary of and within a hexagon HIJKLM in a triangular compositional diagram of a ternary-system solid solution shown in FIG. 2, the vertices H, I, J, K, L and M of said hexagon being given by: x y z ______________________________________ H 0.10 0.80 0.10 I 0.01 0.71 0.28 J 0.01 0.09 0.90 K 0.10 0.00 0.90 L 0.60 0.00 0.40 M 0.60 0.30 0.10, ______________________________________ said process comprising the steps of: preparing an aqueous soluton of the metallic elements in the mol ratios given in said formula, neutralizing said aqueous solution to provide a suspension of hydroxides of said metallic elements, subjecting said suspension in an autoclave under pressure to a temperature between 150° and 300°C for a time sufficient to produce cyrstalline precipitate of said composition and of an average particle size between 0.02 and 0.2 micron in a mother liquor, and separating said precipitate from said mother liquor.

Claim 6

A process for preparing a composition represented by the formula: Pb(Mn 1/3 .Nb.sub. 2/3) x .Ii.sub. y.Zr.sub. z.O.sub. 3, where x, y and z represent mol ratios, the sum of x, y, and z being equal to 1.00, and x, y and z fall on the boundary of and within a hexagon HIJKLM in a triangular compositional diagram of a ternary-system solid solution shown in FIG. 2, the vertices H, I, J, K, L and M of said hexagon being given by: x y z ______________________________________ H 0.10 0.80 0.10 I 0.01 0.71 0.28 J 0.01 0.09 0.90 K 0.10 0.00 0.90 L 0.60 0.00 0.40 M 0.60 0.30 0.10, ______________________________________ said process comprising the steps of: preparing an aqueous soluton of the metallic elements in the mol ratios given in said formula, neutralizing said aqueous solution to provide a suspension of hydroxides of said metallic elements, subjecting said suspension in an autoclave under pressure to a temperature between 150° and 300°C for a time sufficient to produce cyrstalline precipitate of said composition and of an average particle size between 0.02 and 0.2 micron in a mother liquor, and separating said precipitate from said mother liquor.

Claim 7

A process for preparing a composition represented by the formula: Pb(Mn 1/3 .Ia.sub. 2/3) x .Ii.sub. Y.Zr.sub. z O.sub. 3, where x, y and z represent mol ratios, the sum of x, y and z being equal to 1.00, and x, y and z fall on the boundary of and within a nonagon NOPQRSTUV in a triangular compositional diagram of a ternary-system solid solution shown in FIG. 3, the vertices N, O, P, Q, R, S, T, U, and V of said nonagon being given by: x y z ______________________________________ N 0.01 0.55 0.44 0 0.01 0.09 0.90 P 0.05 0.05 0.90 Q 0.20 0.05 0.75 R 0.50 0.23 0.27 S 0.30 0.50 0.20 T 0.10 0.70 0.20 U 0.05 0.70 0.25 V 0.02 0.68 0.30, ______________________________________ said process comprising the steps of: preparing an aqueous solution of the metallic elements in the mol ratios given in said formula, neutralizing said aqueous solution to provide a suspension of hydroxides of said metallic elements, subjecting said suspension in an autoclave under pressure to a temperature between 150° and 300°C for a time sufficient to produce cyrstalline precipitate of said composition and of an average particle size between 0.02 and 0.2 micron in a mother liquor, and separating said precipitate from said mother liquor.

Claim 8

A process for preparing a composition represented by the formula: Pb(Mn 1/3 .Ia.sub. 2/3) x .Ii.sub. Y.Zr.sub. z O.sub. 3, where x, y and z represent mol ratios, the sum of x, y and z being equal to 1.00, and x, y and z fall on the boundary of and within a nonagon NOPQRSTUV in a triangular compositional diagram of a ternary-system solid solution shown in FIG. 3, the vertices N, O, P, Q, R, S, T, U, and V of said nonagon being given by: x y z ______________________________________ N 0.01 0.55 0.44 0 0.01 0.09 0.90 P 0.05 0.05 0.90 Q 0.20 0.05 0.75 R 0.50 0.23 0.27 S 0.30 0.50 0.20 T 0.10 0.70 0.20 U 0.05 0.70 0.25 V 0.02 0.68 0.30, ______________________________________ said process comprising the steps of: preparing an aqueous solution of the metallic elements in the mol ratios given in said formula, neutralizing said aqueous solution to provide a suspension of hydroxides of said metallic elements, subjecting said suspension in an autoclave under pressure to a temperature between 150° and 300°C for a time sufficient to produce cyrstalline precipitate of said composition and of an average particle size between 0.02 and 0.2 micron in a mother liquor, and separating said precipitate from said mother liquor.