Piezoelectric ceramics and piezoelectric device
AssigneeTDK Corporation
InventorsMasahito Furukawa, Kazutaka Suzuki, Yoshiko Gokita, Takumi Satou, Keisuke Itakura
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Abstract
Manganese oxide and tantalum oxide are added to a piezoelectric ceramic composition based on lead zinc-niobate titanate zirconate. The composition is suitable for piezo-electric transformers since its mechanical quality factor (Qm) is improved without reducing its electromechanical coupling coefficient (k31), and good high-power properties and high mechanical strength are obtained. In another embodiment, manganese oxide and at least one of antimony oxide and niobium oxide are added to a piezoelectric ceramic composition based on lead zinc-niobate titanate zirconate.
Claims18
A piezoelectric ceramic composition, comprising:
- a main component represented by the formula:
- (Pb1−aAa)(Zn⅓Nb⅔)xTiyZrzO3
- wherein A is at least one metal element selected from the group consisting of calcium, strontium, and barium;
- and
- wherein letters a, x, y, and z representative of molar ratios are numbers;
- and
- wherein 0≦a≦0.1, x+y+z=1, 0.05≦x≦0.4, 0.1≦y≦0.5, and 0.2≦z≦0.6;
- and
- an auxiliary component containing manganese oxide and either antimony oxide or antimony oxide and niobium oxide, the content of manganese oxide calculated as MnO2 being 0.05 to 3% by weight based on the weight of the main component and the total content of antimony oxide and niobium oxide, calculated as Sb2O3 and Nb2O5, respectively, being 0.05 to 5% by weight based on the weight of the main component.
A piezoelectric ceramic composition, comprising:
- a main component represented by the formula:
- (Pb1−aAa)(Zn⅓Nb⅔)xTiyZrzO3
- wherein A is at least one metal element selected from the group consisting of calcium, strontium, and barium;
- and
- wherein letters a, x, y, and z representative of molar ratios are numbers;
- and
- wherein 0≦a≦0.1, x+y+z=1, 0.05≦x≦0.4, 0.1≦y≦0.5, and 0.2≦z≦0.6;
- and
- an auxiliary component containing manganese oxide and either antimony oxide or antimony oxide and niobium oxide, the content of manganese oxide calculated as MnO2 being 0.05 to 3% by weight based on the weight of the main component and the total content of antimony oxide and niobium oxide, calculated as Sb2O3 and Nb2O5, respectively, being 0.05 to 5% by weight based on the weight of the main component;
- wherein said piezoelectric ceramic composition has a mechanical quality factor, QM, suitable for piezoelectric transformers and ultrasonic motors.
A piezoelectric ceramic composition, comprising:
- a main component represented by the formula:
- (Pb1−aAa)(Zn⅓Nb⅔)xTiyZrzO3;
- wherein A is at least one metal element selected from the group consisting of calcium, strontium, and barium;
- wherein letters a, x, y, and z representative of molar ratios are numbers;
- and
- wherein 0≦a≦0.1, x+y+z=1, 0.05≦x≦0.4, 0.1≦y≦0.5, and 0.2≦z≦0.6;
- and
- an auxiliary component containing 0.05 to 3% by weight calculated as MnO2 of manganese oxide and 0.05 to 1.5% by weight calculated as Ta2O5 of tantalum oxide, based on the weight of the main component;
- wherein said piezoelectric ceramic composition has a mechanical quality factor, QM, suitable for piezoelectric transformers and ultrasonic motors.
Dependencies are inferred from the claim text.