Magneto-Optic Properties of CrTe Films Prepared by Sequential Evaporation

A study was made of the magnetic properties of CrTe films relevant to magneto-optic memory applications. Polar-Faraday rotation measurements in the visible and near infrared were taken on CrTe films prepared by sequential deposition of layers of Cr–Te–Cr on cleaved mica substrates. The Faraday rotation and absorption decreased respectively from 0.5×105°/cm at 0.55 μm to 0.4×105°/cm at 1 μm and 2×105 cm−1 at 0.5 μm to 0.6×105 cm−1 at 2.5 μm. The rotation and coercive field decreased with the magnetization and vanished at the Curie temperature (∼70°C). The polar remanence ratio was 0.2. An in-plane magnetization curve had a remanence ratio of 0.8, a saturation induction (4πMs) of 1015 G and a coercive field of 117 Oe. The measurements indicate significant advantages for CrTe films in memory applications if the epitaxial growth can be improved resulting in higher polar remanence.