Enhanced Electrostrictive Properties and Thermal Stability in Zn-Modified 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 Ceramics

Abstract

A 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 (PMNT) relaxor ferroelectric ceramic is a good dielectric and electrostrictive actuator material. Nevertheless, important engineering problems of further enhancing its electrostrictive effect and increasing its thermal stability must be solved to promote its applications. In this work, the Zn-doped PMNT (PMNT/xZn2+) ceramics were prepared by the niobite precursor synthesis method. The transition of the PMNT/xZn2+ ceramics from relaxor ferroelectric to normal ferroelectric was realized, increasing the residual polarization (Pr), saturation polarization (Pm), the ferroelectric-paraelectric transition temperature at emax (Tm) and electric field induced strain (S) from x = 0.0 (Pr = 5.3294 μC/cm2, Pm = 26.6690 μC/cm2, Tm = 45°C, S = 1.08‰) to x = 8.0 (Pr = 19.9005 μC/cm2, Pm = 30.3718 μC/cm2, Tm = 70°C, S = 1.42‰). In addition, the upper temperature limit of the materials with a large electrostrictive effect (greater than 1‰) was extended from 40°C to 80°C. The main reason for these improved properties is that the magnesium ions were replaced by the highly reactive zinc ions at the B-site of the ferroelectric perovskite structure during the sintering and formed a certain amount of component segregation that increased the size of the polar nanoregions/domains and improved the polarizability of the materials.