Anomalous Hall effect and anisotropic magnetoresistance of molecular beam epitaxy grown Cr2Te3 thin films

High-quality Cr2Te3 epitaxial thin films with thicknesses ranging from 2.5 to 30 nm have been epitaxially grown on SrTiO3(1 1 1) single-crystal substrates using molecular beam epitaxy. The optimal growth temperature of the films was found to be 275 C. All Cr2Te3 films show semiconductor-to-metal transition which is coupled with the paramagnetic-to-ferromagnetic transition at TC = 175 K. Consequently, all Cr2Te3 films show negative magnetoresistance effect which is strongest near TC and can be understood within the framework of electronic phase separation scenario. Both anomalous Hall effect and out-of-plane magnetic hysteresis loops show that all Cr2Te3 films have perpendicular magnetic anisotropy with the easy magnetization axis along the c-axis of the films. With decreasing film thickness the coercivity increases and reaches 10 kOe for the thinnest 2.5-nm film. Magneto resistance measurements at different angles between the direction of the magnetic field and the easy magnetization axis reveal that Cr2Te3 films show anisotropic magnetoresistance whose out-of-plane values are larger than those of in-plane ones.