Effects of CaTiO3 on crystal structures and dielectric properties of Ba(Zn1/3Nb2/3)O3 ceramics via X-ray diffraction and Raman spectroscopy

Abstract

Ba(Zn1/3Nb2/3)O3–CaTiO3 (BZN–CT) ceramics were synthesized at 1,395 °C for 4 h using a conventional solid-state sintering technique, with CT contents of 0, 30, 60, 75, and 90 wt%. Crystal structures were analyzed by X-ray diffraction, and vibrational modes were obtained by Raman spectroscopy to evaluate the correlation between crystal structures, dielectric properties, and phonon modes of these ceramics. Increasing CT content can remarkably affect the crystal structures and dielectric properties of BZN–CT ceramics. Crystal symmetries decrease with CT concentration from cubic to hexagonal structure. The lattice constant and the degree of order also change accordingly. The ordered phases transform from 1:1 to 1:2 ordered structure with changing crystal structures. The relationship between the Raman shifts, the FWHM values, and the dielectric properties were obtained by Raman spectral analyses.