Epitaxial growth of Cd1−xMnxTe films by ionized-cluster beams and their magneto-optical properties

Abstract

Epitaxial growth of Cd1−xMnxTe films with x ranging from 0 to 0.76 has been investigated on sapphire (0001) substrates using the ionized-cluster beam method. Magneto-optical properties of the films are discussed using Kramers–Kronig relation. Epitaxial films in the form of a single crystal can be obtained at low substrate temperatures up to 300 °C by the reactive composing of an accelerated CdTe cluster beam and a neutral MnTe cluster beam. When CdTe clusters are only ionized and accelerated, the composition of grown films varies largely, depending on the acceleration voltage. Faraday rotation for Cd1−xMnxTe films represents a band-edge dispersion, and the intensity increases as Mn concentration x increases; for the film with x=0.76, the maximum value of the Verdet constant was 0.72 °/cm G, which was two orders of magnitude larger than that of a CdTe (x=0) film. The magneto-optical figure of merit θF/α (H=5 kOe) for a Cd1−xMnxTe (x=0.76) epitaxial film was estimated to be about 400 ° at 660 nm.