Characteristics of Thin Films of Ferromagnetic Semiconductor Fe1.1Ti0.9O3−δ Under the Pulsed Laser Deposition Method at Different Substrate Temperatures.

In this study, epitaxial Fe1.1Ti0.9O3−δ thin films with a smooth surface were prepared by adjusting the substrate temperature (TS) and via pulsed laser deposition (PLD) in Ar gas and α-Al2O3 (001) substrate. During the study of the optical properties and magnetism of the thin film samples, it was established that all thin films grown in Ar gas were hypoxic, having more oxygen vacancies and widening the optical band gap of the thin films significantly. The substrate temperature has a significant effect on the crystallization and magnetism of the thin films. It was established that the crystallization of a film at TS = 800 °C is the best, and the saturation magnetization reaches 172.5 emu/cc. The coercivity of films at TS = 600 °C reaches 15 kOe affected by film stress and oxygen vacancies, which is reportedly the maximum value in (1 − x)Fe2O3 − xFeTiO3. Thereafter, it decreases rapidly with the increase in TS, resulting in lattice relaxation, stress reduction, and coercivity reduction. Oxygen vacancies affect the electrical properties in thin films. In contrast to bulk materials, we established that the conduction mechanism of films changes from thermally activated transition to programmed transition with decreasing temperature. [ABSTRACT FROM AUTHOR]