The Study of Ferromagnetic Properties of Diluted Magnetic Semiconductor Ga1−xMnxAs

Abstract

The effect of temperature and dopant ion concentration on the ferromagnetic properties of Ga1−xMnxAs was investigated theoretically. A Heisenberg type model Hamiltonian which incorporates the spin exchange interaction of electrons was considered and solved employing the equation of motion approach of Green’s function formalism. Theoretical expressions which relate magnon density, magnon heat capacity, reduced magnetization and Curie temperature to concentration of the dopant ion (x = 0.02, x = 0.03, x = 0.05) and temperature of the system were obtained from the spectrum of the Green’s function. Our theoretical results indicated the rise in magnon number and their heat capacity with respect to temperature. However, we observed the suppression of these parameters with respect to concentration of the dopant ion. The results also revealed the enhancement of system’s magnetization and Curie temperature with rise in dopant concentration. Our results also revealed the suppression of system’s magnetization with temperature.