Spin-phonon coupling in scandium doped gallium ferrite

Abstract

We embarked on a study of Scandium (Sc) doped (onto Ga site) gallium ferrite (GaFeO₃) and found remarkable magnetic properties. In both doped as well as parent compounds, there were three types of Fe³⁺ ions (depending on the symmetry) with the structure conforming to space group Pna2₁ (Sp. Grp. No. 33) below room temperature down to 5 K. We also found that all Fe³⁺ ions occupy octahedral sites, and carry high spin moment. For the higher Sc substituted sample (Ga_1−xSc_xFeO₃: x = 0.3), a canted magnetic ordered state is found. Spin-phonon coupling below Néel temperature was observed in doped compounds. Our results indicated that Sc doping in octahedral site modifies spin-phonon interactions of the parent compound. The spin-phonon coupling strength was estimated for the first time in these Sc substituted compounds.