1202.6233 (M. Sawicki et al.)

Origin of low-temperature magnetic ordering in Ga$_{1-x}$Mn$_x$N    [PDF]

M. Sawicki, T. Devillers, S. Gałȩski, C. Simserides, S. Dobkowska, B. Faina, A. Grois, A. Navarro-Quezada, K. N. Trohidou, J. A. Majewski, T. Dietl, A. Bonanni

By employing highly sensitive millikelvin SQUID magnetometry, the magnitude of the Curie temperature as a function of the Mn concentration $x$ is determined for thoroughly characterized Ga$_{1-x}$Mn$_x$N. The interpretation of the results in the frame of tight binding theory and of Monte Carlo simulations, allows us to assign the spin interaction to ferromagnetic superexchange and to benchmark the accuracy of state-of-the-art {\em ab initio} methods in predicting the magnetic characteristics of dilute magnetic insulators.

View original: http://arxiv.org/abs/1202.6233