Fe doping-stabilized γ-Ga2O3 thin films with a high room temperature saturation magnetic moment

Abstract

Saturation magnetic moment (M_sm) is a key evaluation parameter of diluted magnetic semiconductors (DMSs). The higher the M_sm, the more widespread the applications of electron spin for non-volatile information manipulation and storage. In this paper, first-principles simulations predicted that cation-deficient γ-Ga₂O₃, having an intrinsic magnetic moment per formula unit cell of about 1 μ_B, is an inherent candidate to prepare DMS with high M_sm. To activate the potential of its magnetism, Fe was introduced as a dopant. A thermostable Fe-doped γ-Ga₂O₃ thin film with high room temperature (RT) M_sm of 5.73 μ_B/Fe was first obtained using the laser molecular beam epitaxy (L-MBE) technique. While combining theoretical calculations and experimental data, the main source of RT ferromagnetism could be ascribed to the strong ferromagnetic (FM) coupling between Fe ions, p–d orbital overlap of the Fe–O bond, and defects. Our results provide a feasible model for designing high-performance γ-Ga₂O₃-based DMSs.