Magnetic and magneto-optical properties in diluted magnetic semiconductors: Cd1-x-yMnxFeyTe single crystals

Abstract

We investigated the magneto-optical properties of diluted magnetic semiconductor Cd1-x-yMnxFeyTe (x∼0.38) single crystals grown using a vertical Bridgman method. Faraday rotation as a function of photon energy with various Fe compositions for CdMnFeTe in the temperature range of 10-300 K has been measured. The Verdet dispersion curves were enhanced near the fundamental band gap energy. The Verdet constant becomes larger since the effect of the sp-d exchange interaction is enhanced as the temperature is lowered. At 10 K, the Verdet constants of the Faraday rotation for the samples with y=0, 0.017, 0.038, and 0.058 were observed to be -0.93, -1.36, -1.65, and -1.94 deg/G cm at 610 nm, respectively. The Verdet constant showed a maximum for the sample with y=0.058, and the value is approximately four times larger than that of the Cd0.62Mn0.38Te crystal, and this behavior agrees well with that of the magnetic susceptibility.