Effect of Y2O3Doping on the Structure and Piezoelectric Properties of BCZT Ceramics

The [50(Ba0.7Ca0.3)TiO3]-50[Ba(Zr0.2Ti0.8)O3] + xmol% Y2O3 lead-free ceramics(x=0,0.2,0.4,0.6,0.8 and 1.0) were fabricated successfully by the traditional solid-state reaction. And the microstructures, phase structure, ferroelectric and piezoelectric properties were investigated for the Y2O3-modified [50(Ba0.7Ca0.3)TiO3]-50[Ba(Zr0.2Ti0.8)O3] lead-free piezoelectric ceramics. The appropriate dopant could reduce the pores in the specimens and enhance the ferroelectric properties. The optimal piezoelectric properties d33of the lead free ceramic is 494pm/V.And the 50BCT-50BZT ceramics with 0.4mol% Y2O3possess the optimal ferroelectric properties,Pr=6. 38μC/cm. Introduction Ferroelectric and piezoelectric materials are widely used in various devices such as sensors, actuators and memories.PZT is the dominant ferroelectric and piezoelectric materials. However, its toxicity can't be ignored during applying and casting aside. In recent years, the innovative environment friendly materials have attracted increasing attention for the substitution of Pb-based ceramics. There are several lead free ferroelectric materials, such as BT based ceramics, NBT and KNN based ceramics[1-4]. Since 2009, the lead-free [Ba(Zr0.2Ti0.8)O3]-x[(Ba0.7Ca0.3)TiO3] piezoelectric ceramic, BCZT, were designed by Ren and Liu, whichhas been attracted increasing attentions for its excellent piezoelectric property at morphotropic phase boundary MPB[5]. The maximum of piezoelectric coefficient reaches 620pC/N, which is regarded as the promising substitution of Pb-ceramic. Thus,there are a series of studies on BCT-BZT lead-free piezoceramics were published[8,14-16]. For instance, Ma et al. have prepared Sb2O3 modified (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 lead-free piezoelectric ceramics by conventional sintering and enhanced electric properties ofd33~556 pC/N,kp~52%, and Ɛr~3,895 was obtained for the BCZT-xSb ceramic with x=0.1%[6]. Jiang et al. fabricated the Ba0.85Ca0.15Ti0.90Zr0.10O3+xmol% MnO2 lead-free ceramics by a conventional sintering method[7]. The 0.25 mol% MnO2addition promoted grain growth and improved the ferroelectricity of the ceramics. The ceramic specimens with x=0.25 exhibited the optimal piezoelectric properties (d*33=306pC/N andkp=42.2%,respectively). In this work, Y element was added into BCZT lead-free piezoelectric ceramic to improve the ferroelectric and piezoelectric properties. And the effectsY2O3on the structure, piezoelectric and dielectric properties are investigated. Experimental Procedure 50BCT-50BZT ceramic with xmol%Y2O3 (x=0.0,0.2,0.4,0.6,0.8and1.0)were prepared by traditional solid-state reaction. BaCO3(99 %, Sinopharm Chemical Reagent Co., Ltd,China), CaCO3(99 %, Sinopharm Chemical Reagent Co.,Ltd, China), TiO2(98 %, Sinopharm Chemical Reagent Co., Ltd, China), ZrO2(99 %, Sinopharm Chemical Reagent Co., Ltd, China), and Y2O3(99.99 %, Sinopharm Chemical Reagent Co., Ltd, China) were used as the raw materials. The International Conference on Manufacturing Engineering and Intelligent Materials (ICMEIM 2017) Copyright © 2017, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Engineering, volume 100