Piezoelectric properties of tungsten doped PZT type materials

Abstract

Piezoelectric properties of four tungsten doped samples of PZT type were determined as a function of composition. The samples were prepared by the usual ceramic technique from raw oxide of 99.9% purity. All compositions exhibited maximum values for the density at a sintering temperature of 1180°C with a soaking time of 4h, so that the piezoelectric properties were determined on the samples sintered at this temperature only. The results showed that the piezoelectric properties were not drastically modified by the doping level, but dopings higher than 5% at. slightly alter the properties. The best values obtained for the piezoelectric parameters were: density ρ= 7.7 g/cm³; dielectric constants, ε_r= 1410; electromechanical coupling factors, k_p = 0.63, and k_T = 0.55; mechanical quality factor Q_m ≈ 90; piezoelectric voltage constant d₃₃ = 470.10⁻¹² m/V; piezoelectric charge constant g33 = 25.10⁻³ Vm/N. These values show that tungsten doped materials are piezoelectric soft type ceramics of high quality that can be successfully used for manufacturing ultrasonic transducers