Giant Faraday rotation in Cd1-xMnxTe (0 < x < 0.82) crystals

Abstract

We investigated the magneto-optical properties of diluted magnetic semiconductors Cd1-xMnxTe crystals grown using a vertical Bridgman method. This material crystallizes in the zinc-blende structure for values of x < 0.82. The band-gap energy was depended on Mn mole fraction x linearly and increased with decreasing temperature. The increase of the energy gap with increasing x may be due to a decrease in the lattice constant. Faraday rotation as a function of photon energy with various Mn compositions for CdMnTe in the temperature range of 10-300 K has been measured. The Faraday rotation was increased as the photon energy increased near to that of the fundamental band gap. Verdet constant becomes larger since the effect of the sp-d exchange interaction is enhanced as the temperature is lowered.