Raman Scattering Investigation of Skutterudite Compounds
نویسندگان
چکیده
Raman scattering spectra of filled skutterudite RT4X12 (R=La, Ce, Pr, Nd, Sm and Y, T=Fe, Ru and Os, and X=Sb and P) and unfilled skutterudite CoP3 have been measured. All first-order Raman active phonons, which are due to the vibration of pnictogens, are observed. In addition, the crystal field excitations in PrRu4P12 spectra and the 2 order phonons including rare-earth vibrations in SmRu4P12 and ROs4Sb12 are also observed. The 2order phonons can be observed for the sample with the larger cage space. The peak intensity of the 2order phonons decreases with decreasing temperature and vanishes at low temperature. Such a temperature dependence suggests that the 2order phonons are thermally excited and due to independent vibrations of the rare-earth ions, that is rattler motion. keyword Skutterudite, Raman scattering, rattling vibration Corresponding Author : Norio Ogita Tel. +81-82-424-6550 Fax. +81-82-424-0757 E-mail : [email protected]
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