Correlation between crystal structures and vibration modes of Ba[(Zn1−x Mg x )1/3Nb2/3]O3 ceramics as a function of sintering temperatures

Abstract

Ba[(Zn1−x Mg x )1/3Nb2/3]O3 (short for BZMN, x = 0.4, 0.6, 0.8) solid solution ceramics were sintered by conventional solid-state sintering technique at different temperatures. Effects of sintering temperatures on phonon modes and crystal structures of BZMN ceramics were investigated by X-ray diffraction and vibration spectra (Raman spectroscopy as well as Fourier transform far-infrared reflection spectroscopy) techniques. The results reveal that sintering temperatures have an obviously influence on phonon modes, which are closely related to the 1:2 ordered structures. For the samples where x = 0.4, they possess the cubic structure (Pm3m), and the ordering degree decreases with the increase in the temperature. For the samples where x = 0.6, phase transition occurs after sintered at 1,500 °C, i.e., a 1:2 ordered monoclinic unit cell is formed. For the samples where x = 0.8, they possess the hexagonal structures ( $$P\bar{3}m1$$ ), and the ordering degree increases with the increase in the temperatures.