Microstructure, dielectric and piezoelectric properties of (Pt_(1-x)Sr_x) Nb_(1.96)Ti_(0.05)O_6 ceramics

摘要

(Pb_(1-x)Sr_x)Nb_(1.96)Ti_(0.05)O_6 with 2 wt% excess PbO (x = 0, 0.02, 0.04, 0.06, 0.08) piezoelectric ceramics with high Curie temperature were fabricated via the conventional solid state reaction method. Effects of Sr~(2+) amount on crystallite structure, microstructure, dielectric and piezoelectric properties were studied. The substitution of Sr~(2+) ions for Pb~(2+) ions is effective to lower sintering temperatures. X-ray diffraction patterns indicate that all ceramics form the single orthorhombic ferroelectric phase. The doping of Sr~(2+) ions facilitates improving densiflcation of the ceramics. Grain size and lattice parameters of the ceramics vary with the change of the Sr~(2+) contents. Both Curie temperature and maximum dielectric constant change with increasing the Sr~(2+) amounts. The dielectric constant data were also studied using the Curie -Weiss law and modified Curie-Weiss law. The ceramic with x = 0.04 possesses excellent piezoelectric and dielectric properties, presenting a high potential to be used in high-temperature applications as piezoelectric transducers.