Influence of material composition on 3rd nonlinear piezoelectric coefficient in lead zirconate titanate ceramics

The relationship between crystal structure and nonlinear piezoelectric coef ficient was investigated in lead zirconate titanate-lead antimony niobate c eramics with various Zr/(Zr+Ti) ratios and MnO contents, using rectangular- bar-shaped samples. The electromechanical coupling factor k(31) and 3rd non linear piezoelectric coefficient xi (31) were measured near the resonance f requency of length-extensional 1/2 lambda mode vibration. Among the ceramic s having various Zr/(Zr+Ti) ratios, the minimum xi (31) was observed when t he crystal structure of the sample was just on the morphotropic phase bound ary, at which k(31) showed the maximum value. The xi (31) also decreased wi th the increase of MnO additive.