Technology and properties of high-temperature piezoceramic materials based on phases of the system (1 – у)(Bi0.8Ba0.2)Fe0.8Ti0.2O3 – у(Ba0.85Ca0.15)Ti0.90Zr0.10O3

In technology, using as precursors Fe(III) and Bi(III) nitrates, peroxo-nitrate complexes Ti(IV) and Zr(IV), as well as barium and calcium hydroxides, ultrafine powders of the (1 – у)Bi0.8Ba0.2Fe0.8Ti0.2O3 – уBa0.85Ca0.15Ti0.9Zr0.1O3 (у = 0,05 – 0,30). To reduce the electrical conductivity of ceramic samples made from these powders, the basic phases were alloyed with manganese compounds. To increase the d33 values of the piezoelectric elements, as well as to increase their operating temperature, a special sintering regime involving air hardening of the ceramic samples was used. The best samples of piezoceramics produced by the proposed technology have a Curie temperature above 550 °C and longitudinal piezoelectric modulus (standard conditions) values d33 ≥ 125 pC/N and their operating temperature reaches 340 – 350 °C.