Effects of piezoelectric and dielectric properties of (Bi0.5Na0.5) TiO3-Ba (Ti, Zr) O3ceramics

Abstract

Abstract Lead-free piezoelectric ceramics Zr and Mn-doped Ba (ZrxTi1-x) O3-0.5 mol% MnO2 (BZT100x-Mn, x=0.04, 0.045, 0.05, 0.055, 0.06 and 0.065) have been fabricated by the conventional solid-state reaction technique. The effects of Zr on the microstructure and electrical properties of the samples have been studied. The results revealed that the specimens exhibit the perovskite structure and a small amount of MnO2 can improve effectively the densification and electrical insulation of the ceramics. Because of high densification, good electrical insulation the donor-and acceptor-doping effects of MnO2, the piezoelectric and dielectric properties of ceramics are improved considerably. The ceramics shows an excellent piezoelectric strain constant d33 as 213 pC/N. A distinct positive temperature coefficient of resistance (PTCR) effect over a wide temperature range has been observed in all samples. With the addition of 0.5 mol% MnO2, the sample Ba(ZrxTi1-x)O3-0.5 mol% MnO2 with x=0.06 (BZT6-Mn) ceramics display low ρ values of 103 Ω cm at room temperature and their abrupt changes of 102-103 near Curie Temperature.