Raman scattering study of CeRhAs

Temperature dependence of Raman scattering spectra of Kondo insulator CeRhAs has been measured. With decreasing temperature, the phonon peaks split into doublet and triplet at about 370 K and below 165 K, respectively. The splitting is caused by a zone-folding due to the lattice modulations. The temperature dependence of the background intensity below 70 cm-1 is well explained by the resonance level model with V-shaped gap