Polymorphic phase transition and piezoelectric properties of (Ba1-xCax)(Ti0.9Zr0.1)O3 lead-free ceramics

Lead-free (Ba1-xCax)(Ti0.9Zr0.1)O-3 (x=0.12-0.18) (BCZT) ceramics were prepared successfully using a solid-state reaction technique. The polymorphic phase transitions (PPT) from rhombohedral to orthorhombic phase around room temperature were identified in the composition range 0.14 < x < 0.18. The samples at x=0.16, showing coexistence of rhombohedral and orthorhombic phase, exhibit enhanced piezoelectric and dielectric properties of d(33)=328 pC/N, k(p)=37.6% and epsilon'=4800. With the increase of Ca content, the polymorphic phase transitions shift to lower temperature and cannot be observed above room temperature at x >= 0.18. (C) 2010 Elsevier B.V. All rights reserved.