A Monte Carlo Study of Critical Properties of Strongly Diluted Magnetic Semiconductor (Ga, Mn) As

Within a Monte Carlo technique we examine critical properties of diluted bulk magnetic semiconductor (Ga, Mn) As modeled by a strongly diluted ferromagnetic Heisenberg spin-5/2 system on a face centered cubic lattice. We assumed that 5% of Ga atoms is substituted by Mn atoms and the interaction between them is of the RKKY-type. The considered system is randomly quenched and a double average was performed: firstly, over the Boltzmann probability distribution and secondly - over 2048 configurations related to the quenched disorder. We estimated the critical temperature: T-c = 97 +/- 6 K, which is in agreement with the experiment.