X-ray diffraction and Raman scattering investigations on Ba[Mg_((1-x)/3)Zr_xTa_(2(1-x)/3)]O_3 solid solutions

摘要

Ba[Mg_((1-x)/3)Zr_xTa_(2(1-x)/3)]O_3 (BMZT, x = 0, 0.05,0.10,0.20,0.30) solid solution ceramics were synthesized via the conventional solid-state reaction method. The crystal structures were studied via X-ray diffraction, and lattice vibrational modes were obtained via Raman spectroscopy. The results show that crystal symmetry increases with Zr~(4+) concentration from hexagonal to cubic structure, and the lattice constant as well as the degree of order decrease, accordingly. The ordered phases are transformed from the 1:2 ordered structure to the 1:1 ordered structure. The Raman shifts of the A_(lg)(O) modes have a positive correlation with the temperature coefficients of constant from x= 0 to x = 0.30 and also a positive correlation with the dielectric constants when x ≥ 0.20, as well as an inverse correlation with the dielectric constants when x ≤ 0.20 and the dielectric losses from x = 0 to x = 0.30.