Polymorphic phase transition and enhanced piezoelectric properties in (Ba0.9Ca0.1)(Ti1-xSnx)O3 lead-free ceramics

Lead-free (Ba0.9Ca0.1)(Ti1-xSnx)O-3 (BCTS) (x=0.02-0.1) ceramics were fabricated using conventional solid state reaction method. The effects of Sn substitution on structure and electrical properties of the BCTS ceramics were researched. At room temperature, a polymorphic phase transition (PPT) from tetragonal phase to rhombohedral phase is identified from XRD patterns with increasing Sn content. High piezoelectric coefficient of d(33)=405 pC/N and planar mode electromechanical coupling factor of k(p)=43.2% are obtained for the sample at x=0.06. The ceramic for x=0.06 also shows uniform microstructure that contributes to the excellent electrical properties. These results indicate that this BCTS system with optimal composition is a promising lead-free piezoelectric material. (C) 2012 Elsevier B.V. All rights reserved.