The effects of substrate temperature on the magnetic and magnetotransport properties of Cr1-xTe epitaxial films

Cr1-xTe epitaxial films have been grown on SrTiO3 (1 1 1) single-crystal substrates using molecular beam epitaxy. The effects of substrate temperature on the structural, electronic, and magnetic properties of the Cr1-xTe films are studied. As the substrate temperature increases, the Cr content increases, which results in the increase in the Curie temperature and in-plane magnetization and decrease in the out-of-plane magnetization and coercive field as well as significant changes in magnetoresistance and perpendicular magnetic anisotropy of the Cr1-xTe films. All Cr1-xTe films show metal-to-semiconductor-like transitions which are coupled with paramagnetic-to ferromagnetic transitions whose temperatures depend on the Cr concentration x. Upon the application of magnetic fields, all samples show negative magnetoresistance effect which is strongest near the transitions and can be understood within the framework of electronic phase separation. These results demonstrate that the substrate temperature have significant effects on the magnetic and magnetotransport properties of Cr1-xTe films and should be carefully controlled in order to obtain desired electronic and magnetic properties.