Competing exchange couplings in Sr2CrReO6 Double Perovskite

Super Exchange (SE) coupling and Double Exchange (DE) couplings in the Double Perovskite (DP) Sr2CrReO6 have been calculated by using a new approximation method, proposed in this paper, based on a relation between internal energy per site and magnetization per site. Monte Carlo simulation has been performed, as computational method in the framework of Ising model, to find the exchange couplings that verify the experimental Curie temperature measured under an external field h=1 T. SE exchange coupling has been found equal to −19.992 meV and the DE couplings corresponding respectively to Cr and Re sublattices have been found equal to 18.334 meV and 18.741 meV. Internal energy per site has been calculated.