Effects of local distortion on the electrical properties of lead free perovskite-type electro-ceramics Ba1-xCaxTi0.9Zr0.1O3

Abstract

The electro-ceramic industry has focused their attention on replacing lead-based materials due to their toxic effects and unfavourable environment impact. Barium titanate doped with calcium and zirconium denoted in this work as BCZT is a well-known perovskite-type solid solution. In particular, Ba1-xCaxTi0.9Zr0.1O3 (where x = 0, 0.1 and 0.15) compositions are located near the so called morphotropic phase boundary (MPB): coexistence of ferroelectric phases. This work shows the relationship between the crystal and electronic structure with the dielectric and piezo-ferroelectric properties. The high-resolution X-ray diffraction (HR-XRD) results suggest the coexistence of tetragonal and rhombohedral phases over the obtained compositions. The dielectric analysis indicates a relaxor behaviour with a Curie temperature in a range of 100-120°C. Piezoelectric and ferroelectric evaluation complement the electrical characterization for these compositions. Micro-X-ray absorption near edge spectroscopy (μ-XANES) was performed to monitor possible changes of electronic structure profile due to the local distortions as Ca2+ increases.