Magnetic, dielectric and photo-absorption study of a ferromagnetic semiconductor α-Fe1.4Ga0.6O3

We report the synthesis of α-Fe1.4Ga0.6O3 compound and present its structural phase stability and interesting magnetic, dielectric and photo-absorption properties. In our work Ga doped α-Fe2O3 samples are well stabilized in α phase (rhombohedral crystal structure with space group R3C). Properties of the present composition of Ga doped α-Fe2O3 system are remarkably advanced in comparison with recently most studied FeGaO3 composition. At room temperature the samples are typical soft ferromagnet, as well as direct band gap semiconductor. Dielectric study showed low dielectric loss in the samples with large enhancement of ac conductivity at higher frequencies. Optical absorption in the visible range has been enhanced by 4 to 5%. This composition has exhibited large scope of tailoring room temperature ferromagnetic moment and optical band gap by varying grain size and non-ambient (vacuum) heat treatment of the as prepared samples by mechanical alloying.