Effects of CuO additive on structure and electrical properties of low-temperature sintered Ba0.98Ca0.02Zr0.02Ti0.98O3 lead-free ceramics

Lead-free Ba0.98Ca0.02Zr0.02Ti0.98O3-xmol% (x=0-2.0) CuO ceramics (BCZT-xCu) were fabricated by the traditional solid state reaction technique, and their structure and electrical properties were studied systematically. With the introduction of Cu, the orthorhombic-tetragonal (TO-T) phase transition shifted towards lower temperature, while Curie temperature (T-c) remained at relatively high value of about 120 degrees C. The sintering temperature was reduced by 150 degrees C than that for pure BCZT ceramics while showing equivalent properties. 0.8 mol% Cu modified ceramics showed excellent piezoelectric properties with d(33)=315pC/N and k(p)=44%. Besides these, a relatively high dielectric coefficient (epsilon(r)=2280), a low dielectric loss (tan delta=1.14%), a high remnant polarization (P-r=11.6 mu C/cm(2)) and low coercive field (E-c=0.37 kV/mm) were also obtained on Ba0.98Ca0.02Zr0.02Ti0.98O3-0.8 mol% Cu lead-free ceramics. Moreover, the influence of sintering temperature on the microstructure development and electrical properties of BCZT-0.8 mol% Cu ceramics has also been studied. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.