Phonons in mixed superionic fluorites (BaF2)1�?����?(LaF3)𝑥

[摘要] In recent years, the fluorite-structured solid solutions with the general formula, (MF₂)_{1â€�?�ð�?��?}(RF₃)_ð‘�? (M = Ca, Sr, Ba, Pb and R is a rare-earth element or Y), have been the subject of numerous experimental studies focussed on their superionic properties. The overall cubic crystal symmetry (space group 𝐹ð‘�?3ð‘�?) is conserved up to ð‘�? â‰�? ð‘�?_max, where ð‘�?_max 0.4â€�??0.5 depending on M and R. The zone centre phonons and phonon dispersion along three symmetry directions of the mixed superionic compound (BaF₂)_{1â€�?�ð�?��?}(LaF₃)_ð‘�? have been investigated by applying de Launey angular force model for ð‘�? â‰�? ð‘�?_max. The calculated results are compared and explained with available experimental results.

[学科分类] 材料工程

[关键词] Superionic properties;(MF2)1â€�?�ð�?��?(RF3)𝑥;fast ion conductors.