Anharmonicity and phase stability of antiperovskite Li3OCl

Article

关键词: FUNCTIONAL PERTURBATION-THEORY;    AUGMENTED-WAVE METHOD;    SUPERIONIC CONDUCTORS;    PHONON DISPERSIONS;    LATTICE-VIBRATIONS;    FORCE-CONSTANTS;    PEROVSKITES;    TRANSITIONS;    INSTABILITIES;    HALIDES;   

DOI  :  10.1103/PhysRevB.91.214306

来源: SCIE

【 摘 要 】

A lattice-dynamics study of the cubic Li3OCl antiperovskite, a candidate solid electrolyte in lithium-ion batteries, reveals the presence of dynamical instabilities with respect to rotations of the Li6O octahedra. Calculated energy landscapes in the subspace of unstable octahedral rotational modes are very shallow with at most a 1 meV per formula unit reduction in energy upon breaking the cubic symmetry. While Li3OCl is not stable relative to decomposition into Li2O and LiCl at 0 K, estimates of the vibrational free energy suggest that Li3OCl antiperovskite should become entropically stabilized above approximately 480 K.

【 授权许可】

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