Effect of Ho doping on piezoelectric properties of BCZT ceramics

Lead-free (Ba0.99Ca0.01)(Ti0.98Zr0.02)O-3 (BCZT) + x mol% Ho (x = 0-0.6) ceramics were prepared using solid-state reaction technique. High piezoelectric coefficient of d(33) = 330 pC/N and planar electromechanical coupling factor of k(p) = 40% were obtained at x = 0.2%. Furthermore, greatly enhanced temperature stability of the piezoelectric properties was obtained in the temperature range from 20 to 100 degrees C, in which the Ho doped BCZT ceramics exhibited pure tetragonal phase. With the increase of Ho content, the orthorhombic-tetragonal phase transition shifted towards low temperature, while Curie temperature (T-c) remained at about 120 degrees C. The results indicate that Ho doped BCZT ceramics could be promising candidate as lead-free piezoelectric materials. Crown Copyright (C) 2011 Published by Elsevier Ltd and Techna Group S.r.l. All rights reserved.