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US 11,873,253 B2Granted
Ceramic
AssigneeXaar Technology Limited
InventorsMichael Watson, Angus Condie, Timothy Paul Comyn, Andrew Bell
Life of this patent
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Abstract
There is disclosed a piezoelectric ceramic having the composition: a[PbTiO3]-b[SrTiO3]-c[BiFeO3]-d[(KxBi1-x)TiO3]; wherein 0.4<x<0.6; 0.1<a<0.4; 0.01<b≤0.2; c≥0.05; d≥0.01; and a+b+c+d=1 optionally comprising an A- or B-site metal dopant in an amount of up to 2 at. %.
Claims19
A piezoelectric ceramic comprising:
- a first portion poled in a first direction;
- and
- a second portion poled in a second direction opposite to the first direction, the first and second portions being in contact with each other,
- wherein the first portion and the second portion comprise:
- a Berlincourt d33 value ≥250 pm/V;
- a Curie temperature, Tc, of ≥300° C.;
- and
- a fracture toughness, K1c (×106), of ≥3 MPa×m1/2.
5 more elements
A piezoelectric ceramic having a composition of:
- a[PbTiO3]-b[SrTiO3]-c[BiFeO3]-d[(KxBi1-x)TiO3],
- wherein:
- 0.4≤×≤0.6, 0.1≤a≤0.4, 0.01≤b≤0.2, c≥0.05, d 0.01, and a+b+c+d=1
- the piezoelectric ceramic comprises:
- a first portion poled in a first direction;
- a second portion poled in a second direction opposite to the first direction:
- at least one of an A- metal site dopant or a B- metal site dopant in an amount up to 2 at. % per respective metal site;
- a Berlincourt d33 value ≤ 250 pm/V;
- a Curie temperature, Tc, of ≥ 300° C.;
- and
- a fracture toughness, K1c (×106), of ≥3 MPa×m1/2.
8 more elements
A piezoelectric ceramic having a composition of:
- a[PbTiO3]-b[SrTiO3]-c[BiFeO3]-d[(KxBi1-x)TiO3],
- wherein:
- 0.4≤×0.6, 0.2≤a≤0.3;
- 0.025≤b≤0.125;
- 0.4≤c≤0.6;
- 0.05≤d≤0.25, and a+b+c+d=1;
- b is selected so the piezoelectric material has a Berlincourt d33 value greater than 250 pm/V;
- c is selected so the piezoelectric material has a Curie temperature greater than 300° C.;
- and
- the piezoelectric ceramic comprises a first portion poled in a first direction and a second portion poled in a second direction opposite to the first direction.
7 more elements
Dependencies are inferred from the claim text.