Preparation of hafnium barium titanate ceramics and micro-mechanism of their piezoelectric properties
BaHfxTi1-xO3 ceramics were prepared by traditional solid-state reaction, and their piezoelectric and ferroelectric properties, phase composition, and grain size were characterized and analyzed. The results indicate that all ceramics have pure perovskite structure, and are ferroelectric at room temperature with piezoelectricity. At x<0. 1, the piezoelectric coefficient is 195-327 pC/N. The ceramic at x=0. 02 has the highest piezoelectric coefficient of 327 pC/N, residual polarization strength of 13. 3 μC/cm2 , and average grain size of 37. 2 μm. The high piezoelectric coefficient is due to the large grain size and coexistence of the tetragonal-orthogonal-rhombohedral multiphase.