Vacancies And Spin-Phonon Coupling In Crsi0.8ge0.1te3

We report temperature-dependent Raman scattering and magnetization studies of van der Waals ferromagnetic compound CrSi0.8Ge0.1Te3. Magnetic susceptibility measurements revealed dominant ferromagnetic interactions belowT(C)which shift to the lower values due to the presence of vacancies. A Raman active mode, additional to the ones predicted by symmetry in the parent compounds, has been observed. ThisA(g)symmetry mode most likely emerges as a consequence of the atomic vacancies on Si/Ge site. Presence of the strong spin-phonon coupling at temperature around 210 K is indicated by deviations from conventional phonon self-energy temperature dependence of all analysed modes.