Structural and dielectric properties in the (Ba1-xCax)(Ti0.95Zr0.05)O3 ceramics

Lead-free (Ba1-xCax)(Ti0.95Zr0.05)O-3 (x = 0.05-0.40) (BCZT) ceramics were prepared by solid-state reaction technique. XRD results show that the samples in the composition range of 0.05 <= x <= 0.25 exhibit pure perovskite structures and undergo a polymorphic phase transitions from orthorhombic to tetragonal phase around room temperature. The biphasic structures are detected at x >= 0.30 and the dielectric peaks become broad and dielectric constants decrease with increasing Ca content. Ca replacement at Ba site leads to diffuseness, whereas Ca occupancy at Ti site leads to decrease of the T-c. (C) 2011 Elsevier B. V. All rights reserved.