Piezoelectric Ceramics with Zero Temperature Coefficients of Radial Mode Resonance Frequencies

Piezoelectric ceramics with zero temperature coefficients of radial mode resonance frequencies were developed. The chemical formula of these ceramics is (Pb0.91(La1-αNdα)0.08)(Ti0.92Mn0.02In0.06)O3. In the ceramic system, the temperature coefficient varies from -25×10-6/°C to +40×10-6/°C as the molar ratio of Nd changes from 0 to 1. When α=0.5, the temperature coefficient is less than 1×10-6/°C over the temperature range -10 to +50°C. The electromechanical coupling factor of radial mode is 0.1; mechanical quality factor is 1400; and dielectric constant e33T is 225.