高压物理学报2024，Vol.38Issue(2)：86-92,7.DOI:10.11858/gywlxb.20230771
高压下面心立方CeH9和CeH10动力学性质的第一性原理研究
First-Principles Study of the Dynamics in Face-Centered Cubic CeH9 and CeH10 under High Pressure
摘要
Abstract
Rare-earth metal superhydrides have attracted much attention because of their high-temperature superconductivity.Since experimental measurements can only determine the structures of rare-earth metal atoms in the superhydrides,first-principles calculations have become an important complementary method for a comprehensive understanding on their structures and physical properties.In this work,the elasticity,lattice dynamics and proton dynamics properties of face-centered cubic CeH9 and CeH10 with different hydrogen contents but the same Ce lattice structure are investigated comparatively by first-principles calculations.The low hydrogen content is found to favor the elastic and phonon stabilization of face-centered cubic cerium superhydrides expanding to low pressures.At 100-140 GPa,CeH9 and CeH10 do not have significant proton diffusion at room temperature,but fully transform into the superionic state at 1500 K with diffusion coefficients of 1.6×10-4-1.2×10-4 cm2/s and 1.9×10-4-1.5×10-4 cm2/s;the diffusion coefficient is positively correlated with temperature and hydrogen content,but negatively correlated with pressure.The findings on the laws of pressure,temperature and hydrogen content affecting the structure and dynamics of cerium superhydrides are obtained,which can be used as a reference for the study of other superhydrides.关键词
高压/超氢化物/动力学/超离子态/第一性原理Key words
high pressure/superhydrides/dynamics/superionic states/first-principles分类
数理科学引用本文复制引用
王晓雪,丁雨晴,王晖..高压下面心立方CeH9和CeH10动力学性质的第一性原理研究[J].高压物理学报,2024,38(2):86-92,7.基金项目
国家自然科学基金(11974135) （11974135）
