Synthesis, crystal structure, and magnetic properties of ε-GaIII FxeIII O2−x3 nanorods

A series of ε-GaxFe2−xO3 nanorods, which have orthorhombic structures of Pna21, was prepared by combining the reverse-micelle and the sol-gel methods. The coercive fields at 300 K changed over a wide range between 15.5 kOe (x=0.09) and 0.9 kOe (x=0.83). The measured saturation magnetization (Ms) in the sample for x=0.43 was 46.0 emu g−1 at 4 K but 25.6 emu g−1 at 300 K, which is 1.7 times larger than the Ms of the original ε-Fe2O3. This enhanced value is due to the different occupancies of Ga3+ ions in the four types of Fe sites.