Epitaxial Growth of Room-Temperature Ferrimagnetic Semiconductor Thin Films Based on Fe₃O₄-Fe₂TiO₄ Solid Solution

Abstract

Spinel-type 0.4Fe₃O₄·0.6Fe₂TiO₄ (molar ratio) solid solution thin films have been deposited on c-sapphire substrates by a pulsed laser deposition technique. A single phase of (111)-oriented solid solution can be obtained by adjusting the oxygen partial pressure and substrate temperature. The epitaxial solid solution thin film exhibits ferrimagnetism with Curie temperature above room temperature and is a semiconductor with n-type conduction carriers. Anomalous Hall effect is observed at room temperature for the solid solution thin films, implying the presence of spin-polarized charge carriers.