2 research outputs found
Suppression of carrier induced ferromagnetism by composition and spin fluctuations in diluted magnetic semiconductors
We suggest an approach to account for spatial (composition) and thermal
fluctuations in "disordered" magnetic models (e.g. Heisenberg, Ising) with
given spatial dependence of magnetic spin-spin interaction. Our approach is
based on introduction of fluctuating molecular field (rather than mean field)
acting between the spins. The distribution function of the above field is
derived self-consistently. In general case this function is not Gaussian,
latter asymptotics occurs only at sufficiently large spins (magnetic ions)
concentrations . Our approach permits to derive the equation for a
critical temperature of ferromagnetic phase transition with respect to
the above fluctuations. We apply our theory to the analysis of influence of
composition fluctuations on in diluted magnetic semiconductors (DMS) with
RKKY indirect spin-spin interaction.Comment: 6 pages, 2 figure