Low-energy optical phonon modes in the caged compound LaRu2Zn20

Article

关键词: FILLED SKUTTERUDITE ANTIMONIDES;    MICROSCOPIC DYNAMICS;    RU;    SCATTERING;    FE;    RH;    LA;    CO;   

DOI  :  10.1103/PhysRevB.93.064105

来源: SCIE

【 摘 要 】

We have investigated atomic dynamics of caged compound LaRu2Zn20 by the measurements of specific heat C and inelastic x-ray scattering (IXS). The lattice part of the specific heat C-lat divided by T-3, C-lat/T-3, shows a broad peak at around 15 K, which is reproduced by two Einstein modes with characteristic temperatures of theta(E1) = 35 K and theta(E2) = 82 K, respectively. IXS measurements along the [111] and [110] directions reveal weakly dispersive phonon modes at 3 meV (35 K) and 7 meV (80 K), respectively, whose values agree with the values of theta(E)'s. The first-principles calculation has assigned the 3 meV phonon modes as the optical modes of Zn atoms located at the middle of two La atoms, which is likely to lead to the structural instability.

【 授权许可】

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