Intrinsic ferromagnetic properties of Ti0.94Fe0.06O2/Ti0.94Mn0.06O2 superlattice films for dilute magnetic semiconductor applications

Abstract

Superlattice films have been proposed to get dilute magnetic semiconductor (DMS) with an intrinsic room-temperature ferromagnetism. For a TiO2-based DMS superlattice structure, each layer was alternately doped by two different transition metals (Fe and Mn) and deposited to a thickness of approximately 2.7 A on r-Al2O3(1102) substrates by pulsed laser deposition. Samples of Ti0.94Fe0.06O2 (TiFeO), Ti0.94Mn0.06O2 (TiMnO), and Ti-0.94(Fe0.03Mn0.03)O-2 show a low remanent magnetization and coercive field, as well as superparamagnetic features at room temperature. On the other hand, superlattice films (TiFeO/TiMnO) show a high remanent magnetization and coercive field, resulting in intrinsic ferromagnetic properties. The superlattice films composed of alternating layers of Ti0.94Fe0.06O2 and Ti0.94Mn0.06O2 exhibit intrinsic ferromagnetic properties for dilute magnetic semiconductor applications.