Theoretical studies on phonon density of states in nonstoichiometric palladium hydrides

2nd International Conference on Mining, Material and Metallurgical Engineering

矿业工程;材料科学;冶金学

Anzai, D.^1 ; Matsuo, S.^1 ; Hatakenaka, N.^1 ; Ogita, N.^1 ; Matsuda, K.^2 ; Yasuzuka, S.^3

Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima

739-8521, Japan^1

College of Science and Technology, Nihon University, Tokyo

101-8308, Japan^2

Research Center for Condensed Matter Physics, Hiroshima Institute of Technology, Hiroshima

731-5193, Japan^3

关键词: Collective modes;    Forced oscillators;    High frequency HF;    Non-stoichiometric;    Palladium hydride;    Phonon density of state;    Randomly distributed;    Theoretical study;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/191/1/012019/pdf
DOI  :  10.1088/1757-899X/191/1/012019

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

We investigate the phonon density of states in nonstoichiometric palladium hydrides PdHx, in order to clarify the contribution of lattice vibrations to superconductivity. We employ the Burger-MacLachlan model, which considers a one-dimensional triply-connected diatomic chains with randomly distributed vacancies, focusing on thedirection in the rock-salt lattice of PdHx. The phonon density of states is calculated by the Forced Oscillator Method suitable for random systems. We find that phonon modes at high frequencies change from localized to collective modes with increasing x and the crossover stoichiometry is consistent with that of the appearance of superconductivity. These results support the optical phonon mechanism for superconductivity in PdHx.