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.
