Antiferromagnetic superexchange interaction between Fe3+ ions in Fe3+ doped wide-gap oxide of β-Ga2−xFexO3 (x=0.1, 0.2, 0.3, 0.4)

In the Fe3+ doped wide-gap oxide of β-Ga2−xFexO3 (x=0.1, 0.2, 0.3, 0.4), Rietveld refinements of the X-ray diffraction data show that the Fe3+ ions are preferentially occupied on the octahedral sites. From the measurements of magnetization as a function of magnetic field and inverse molar susceptibility as a function of temperature, it is found that the superexchange interaction between Fe3+ ions via an intermediate oxygen ion is antiferromagnetic. The optical bandgap (Eg) is found to decrease monotonically in energy upon increasing the Fe3+ concentration. Below the Eg edge, optical absorption subspectra are observed to occur at ~1.8 and ~2.7 eV, which are attributed to the d-d transitions of the crystal-field splitting of 3d5 multiplets of the octahedral Fe3+ ion.