Two-magnon Raman spectra in a spin-one ferromagnetic fcc lattice

We calculate the Raman spectral density of states for quadrupolar excitations in a face-centered-cubic ferromagnetic lattice of spin-one ions with single-ion anisotropy in addition to the isotropic dipolar and quadrupolar pair interactions. We show that the qualitative features of the variation of the Raman spectra with $\beta$ (the ratio of the quadrupolar and dipolar coupling) and $d$ (the ratio of the single-ion anisotropy and dipolar coupling) are the same for fcc and sc lattices. In particular, there is always a distinctive peak near the energy for quadrupolar excitation at the zone center, i.e., $2z{\Gamma }^{\mathrm{}\left(1\right)\mathrm{}}(1-\beta )$.