Reduced elastic nonlinearity in Mn modified 0.6(Bi_0.9La_0.1)FeO₃–0.4Pb (Ti,Mn)O₃high power piezoceramics

0.6(Bi0.9La0.1)FeO3-0.4Pb(Ti1-xMnx)O-3 (BLF-PTM) piezoelectric ceramics with different Mn contents were fabricated by a sol-gel process combined with a solid-state reaction method. Coexistence of rhombohedral and tetragonal phases is detected in BLF-PTM. An asymmetric P-E loop with a large internal dipolar field of >20 kV cm(-1) is observed in the poled BLF-PTM ceramics of x = 0.01 and 0.02, which is the typical characteristic of hard piezoelectric materials for higher power applications. The dielectric loss, planar coupling coefficient k(p), mechanical quality factor Q(m), vibration velocity, and Curie temperature of 0.006, 0.338, 418, 1.1 m s(-1), and 470 degrees C have been achieved for BLF-PTM with x = 0.01. Furthermore, the elastic nonlinear phenomena in BLF-PTM are investigated by measuring the vibration strain at high electric fields. Upon using Mn doping, BLF-PTM exhibits a large vibration strain and a small resonance frequency shift. The nonlinear elastic compliance of BLF-PTM for x = 0.01 and 0.02 was dramatically decreased by about two orders of magnitude compared to that of BLF-PT for x = 0.