Structural, morphological and magnetic properties of GaSbMn/Si(111) thin films prepared by radio frequency magnetron sputtering

Abstract

The structural, chemical and magnetic properties of GaSbMn thin films grown by Radio Frequency magnetron sputtering on Si (111) substrates, varying the growth temperature, were studied. X-ray diffraction analysis shows that the samples are polycrystalline with multiple phases, and their crystalline quality improves as the substrate temperature increases. A morphological study was carried out using transmission electron microscopy and scanning electron microscopy, revealing the formation of magnetic nanoparticles and precipitates, which depends on the growth temperature. The electronic structure of the films, studied by X-Ray Photoelectron Spectroscopy, exhibits a closely spaced doublet that arises from the spin-orbital coupling into Ga 2p, Sb 3d, and Mn 2p spectra. Measurements of Magnetization as function of temperature, performed in a low external magnetic field (0.05 T), revealed a ferromagnetic ordering from low temperatures to above room temperature, due to the existence of the multiphases GaSbMn, MnSb and GaMn. The magnetization loops taken at 5 K, 150 K, 298 K and 350 K, show that saturation magnetization depends on the sample preparation temperature. For the sample grown at 573.15 K, saturation magnetization decreases with increasing temperature from 5 to 350 K, while for the sample grown at 773.15 K, it is almost independent of temperature, due to the formation of MnSb and GaMn precipitates embedded into GaSb semiconductor matrix.