Perpendicular magnetic anisotropy and spin glass-like behavior in molecular beam epitaxy grown chromium telluride thin films

摘要

Reflection high energy electron diffraction (RHEED), scanning tunnelingmicroscopy (STM), vibrating sample magnetometry and other physical propertymeasurements are used to investigate the structure, morphology, magnetic andmagneto-transport properties of (001)-oriented Cr$_2$Te$_3$ thin films grown onAl$_2$O$_3$(0001) and Si(111)-(7$\times$7) surfaces by molecular beam epitaxy(MBE). Streaky RHEED patterns indicate flat smooth film growth on bothsubstrates. STM studies show the hexagonal arrangements of surface atoms.Determination of the lattice parameter from atomically resolved STM image isconsistent with the bulk crystal structures. Magnetic measurements show thefilm is ferromagnetic having the Curie temperature of about 180 K, and a spinglass-like behavior was observed below 35 K. Magneto-transport measurementsshow the metallic nature of the film with a perpendicular magnetic anisotropyalong the $c$-axis.