Modified Pb(Yb,Nb)O3-PbZrO3-PbTiO3 ternary system for high temperature applications
Ternary 33Pb(Yb1/2Nb1/2)O-(67-x)PbZrO 3-xPbTiO3 [PYNZ-PTx] were investigated as a function of the PT contents. The maximum value of piezoelectric coefficient (d33) was obtained, being on the order of 540 pm/V with high Curie temperature (Tc) of 375 °C for PYNZ-PT48 composition being regarded as the morphotropic phase boundary (MPB). To further increase its properties, La2O3 with 0.0 mol% ≤ x ≤ 3.0 mol% was substituted for PbO as an A-site in ternary PYNZ-PT48 [PYNZT]. The substitution of La3+ for Pb 2+ in PYNZT was found to increase the tetragonality, but greatly reduced Tc and broadened the dielectric permittivity maximum. The relative permittivity was found to follow a Curie-Weiss Law above the deviation temperature (TD). The optimized properties with d33 of 600 pm/V, maximum dielectric permittivity (εmax) of 22500 (at the Tc = 315 °C and 1 kHz) were obtained in PYNZT-La2.0. 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.