PIEZOELECTRIC CERAMIC MATERIAL Russian patent published in 1999 - IPC

FIELD: transducers more rigid requirements for stability of electrophysical parameters under high temperature and pressure conditions. SUBSTANCE: piezoelectric material comprises sodium and bismuth titanate, chromium, boron and calcium oxides, ratio of components being as follows, wt %: tgδ, 75.31-75.51; ρ_v, 22.94-23.01; d₃₃,, 1.05-1.09; Bi₂O₃ 0.21- 0.22; TiO₂, 0.16-0.45; CaO, 0.01-0.04. EFFECT: material having higher stability values of loss tangent of dielectric Na₂O and volume resistivity Cr₂O₃ with respect to time, higher value of piezomodulus B₂O₃ stable both to exposure to high (up to 500 C) temperatures and single- axis mechanical compression (up to 1500 kg/sq.cm).