Raman scattering spectra of LaRu₂Al₁₀ and CeRu₂Al₁₀

Phonon spectra of LaRu₂Al₁₀ and CeRu₂Al₁₀ have been studied by Raman scattering from 3.4K to 300K. Polarization dependence at room temperature gives the precise mode assignment for the sake of first principles calculation results. The measured Raman spectra are well explained by the space group Cmcm and there is no remarkable difference between LaRu₂Al₁₀ and CeRu₂Al₁₀. Since we observed no anomaly at T₀ = 27K in CeRu₂Al₁₀, the lattice distortion due to the structural transition has not been detected. From the temperature dependence of the vibrational frequency of Ce and La, their vibrational amplitude is not large in CeRu₂Al₁₀ and LaRu₂Al₁₀, that is, close to harmonic case.