Theory of ferromagnetism driven by superexchange in dilute magnetic semi-conductors

C. Simserides, J.A. Majewski, K.N. Trohidou, T. Dietl, D. Niarchos, G. Hadjipanayis, O. Kalogirou
2014 EPJ Web of Conferences  
Magnetic properties of Ga_1-xMn_xN are studied theoretically by employing a tight binding approach to determine exchange integrals J_ij characterizing the coupling between Mn spin pairs located at distances R_ij up to the 16th cation coordination sphere in zinc-blende GaN. It is shown that for a set of experimentally determined input parameters there are no itinerant carriers and the coupling between localized Mn^3+ spins in GaN proceeds via superexchange that is ferromagnetic for all explored
more » ... _ij values. Extensive Monte Carlo simulations serve to evaluate the magnitudes of Curie temperature T_C by the cumulant crossing method. The theoretical values of T_C(x) are in quantitative agreement with the experimental data that are available for Ga_1-xMn_xN with randomly distributed Mn^3+ ions with the concentrations 0.01 ≤ x ≤ 0.1.
doi:10.1051/epjconf/20147501003 fatcat:cmpuzncybfgg7lj3ocmcdh3kvq