Far infrared reflection study on structure–property relationship of Ba[Mg(1−x)/3ZrxTa2(1−x)/3]O3 ceramics

Abstract

Ba[Mg(1−x)/3ZrxTa2(1−x)/3]O3 (BMZT, x = 0, 0.1, 0.2, 0.3) solid solution ceramics were synthesized at 1520 °C for 3 h through the conventional solid-state reaction method. The ceramics were characterized by X-ray diffraction and Far-infrared spectroscopy (FIR) to evaluate the correlations among crystal structures, dielectric properties, and phonon modes. Results show that the FIR active modes near 290 and 415 cm−1 disappeared with increasing Zr4+ concentration, the frequencies of the modes near 230 and 540 cm−1 shifted toward high frequency and their intensities decreased, whereas the frequencies of the modes near 450 cm−1 reached a maximum value at x = 0.1. The crystal structures transformed from hexagonal to pseudo-cubic, and eventually to cubic structure, with increasing Zr4+ concentration. Correlations were established between crystal structures and dielectric properties with vibration modes as a media. The ceramics presented the best dielectric properties when x = 0.2 with a pseudo-cubic structure.