Temperature and Bias Characteristics of Pb(Zr-Ti)O3 Families Ceramics

Abstract

Temperature and bias characteristics of ceramics of Pb(Zr-Ti)O₃ and its families have been measured. Bias dependence can be understood with a schematic model on the reorientations of 180° and 90° domains. Dielectric and elastic anisotropies of the single crystal are expected to be larger in the rhombohedral phase than in the tetragonal one. Temperature dependence under fixed biases have led to a supposition that ε ₁₁ and s ₁₁ are more temperature dependent than ε ₃₃ and s ₃₃, respectively. Physical constants of ceramics are not single-valued functions of polarization P ^*. This fact will support Marutake's criticism on the thermodynamic treatments of ceramics formerly reported. A trial of dividing P ^* into the increment P ₁₈₀ ^* caused by 180°-reversals and that P ₉₀ ^* by 90°-rotations make it possible to understand behaviors of piezoelectric constants d ₃₁ ^*, g ₃₁ ^* and coupling coefficient k _r ^* versus P ^*. Constants d ₃₁ ^* and k _r ^* do not represent the degree of poling, and g ₃₁ ^* will be recommended as its practical measure.