Raman scattering of magnetoelectric gallium ferrite thin films
Résumé
Gallium ferrite, Ga2-xFexO3 (GFO), is a promising magnetoelectric material as it exhibits both magnetic and electric orders close to room temperature. Here, we report a temperature-dependent investigation of GFO thin films with x = 1.0 and 1.4 by using Raman scattering. Our investigation suggests the absence of a structural phase transition of both films in the investigated 90-500 K temperature range, which is similar to earlier observations on bulk samples. We note, however, the occurrence of weak anomalies in the temperature-dependent band position of some phonons, which we attribute to spin-phonon coupling as the anomalies occur close to the Neel temperature of the materials.