Molecular Beam Epitaxy Grown Cr2Te3 Thin Films with Tunable Curie Temperatures for Spintronic Devices

Materials with perpendicular magnetic anisotropy (PMA) effect with high Curie temperature is essential in spintronics applications. Cr2Te3 is a transition metal chalcogenide that demonstrates PMA effect but with a relatively low Curie temperature of about 180 K, significantly limiting its practical application. In this work, we reported the epitaxial growth of Cr2Te3 thin films on Al2O3 substrates with Curie temperature ranging from 165 K to 295 K, closely dependent on the thicknesses and lattice constants of the thin films. To study the physical origin of the improved Curie temperature, structural analysis, magneto-transport and magnetic characterizations were conducted and analyzed in detail. In contrast with previous reports, all the high Curie temperature thin films have electron type carriers instead of hole carriers, which is possibly caused by the Al diffusion from the Al2O3 substrate. Based on the structure and chemical analysis, a phenomenological model based on the degree of coupling between fer...