Remarkably High-Temperature Stability of Bi(Fe^sub 1-x^Al^sub x^)O^sub 3^-BaTiO^sub 3^ Solid Solution with Near-Zero Temperature Coefficient of Piezoelectric Properties

The ... and 0.07, abbreviated as BFA...-BT) lead-free high-temperature ceramics were prepared by the conventional ceramic processing. Systematic investigation on the microstructures, crystalline structures, dielectric and piezoelectric properties, and high-temperature stability of piezoelectric properties was carried out. The crystalline structures of BFA...-BT ceramics evolve from rhombohedral structure with x < 0.01 to the coexistence of rhombohedral structure and pseudocubic phases with x ... 0.01, finally to pseudocubic phases when x > 0.03. Remarkably high-temperature stability with near-zero temperature coefficient of piezoelectric properties (...), together with improved piezoelectric properties has been achieved for x = 0.01 BFA...-BT ceramics. The BFA...-BT(x = 0.01) ceramics simultaneously show the excellent piezoelectric properties of ... = 151 pC/N, ... = 0.31 and super-high-temperature stability of ..., ... = 1 x ... It is considered that the observed strong piezoelectricity and remarkably high-temperature stability should be ascribed to the phase coexistence of rhombohedral and pseudocubic phases. The rhombohedral phases have a positive ... value and the pseudocubic phases possess a negative ... value. Thus, the ... value of BFA...-BT ceramics can be tuned by composition of x. (ProQuest: ... denotes formulae/symbols omitted.)