Epitaxial growth of room-temperature ferrimagnetic semiconductor thin films based on the ilmenite-hematite solid solution

Epitaxial thin films composed of O.7FeTiO₃·0.3Fe ₂O₃ solid solution have been prepared on α-Al ₂O₃ (0001) substrates by a pulsed laser deposition method, and their electrical and magnetic properties have been examined. A single phase of the ordered phase can be obtained under limited deposition conditions: oxygen partial pressure of 1.0×10^-3Pa and substrate temperature of 600-700°C. The as-deposited film is semiconducting and ferrimagnetic below room temperature, while subsequent annealing in vacuum leads to the Curie temperature above room temperature. On the other hand, the thin films with the disordered phase appear to be antiferromagnetic and also insulating.