Monte Carlo simulation for calculating the exchange couplings in Ca2CrNO6 (N = Mo, Re) double perovskites

In the last few years there has been a growing interest in mixed magnetic oxides containing the transition-metal Cr, as they show interesting physical properties and a great ability to use in spintronic, photovoltaic and magnetocaloric applications. Therefore, several publications have appeared documenting Cr-based double perovskites, but very few have explored the promising compounds Ca2CrNO6 (N = Mo, Re). Exchange couplings in Ca2CrNO6 (N = Mo, Re) Double perovskites (DPs) have been fitted by Monte Carlo Simulation (MCS) calculations in the framework of Ising model by using a method based on a relation between internal energy per site and magnetization per site. The exchange couplings JCr−Mo=−1.977meV, JCr−Cr=4.614meV and JMo−Mo=1.481meV have been obtained for Ca2CrMoO6, while JCr−Re=−12.221meV, J'Cr−Cr=11.244meV and JRe-Re=11.492meV have been obtained for Ca2CrReO6. The role of exchange couplings strengths in the magnetism of this class of materials has been discussed. Internal energy per site has been calculated.