Monte Carlo Simulation investigation of the diluted Double Perovskite Sr 2 CrRe x Os 1−x O 6

Abstract

Recently, considerable attention has been paid to the Double Perovskite (DP) Sr2CrOsO6 due to its high magnetic polarization and its high Tc = 720 K. Several publications have appeared documenting some of its properties, but there is still a lack of enough technical and theoretical information about it. Therefore, to better understand how the 5d-Os atoms act on this Cr-based DP, it seems useful to take advantage from knowledge about the most studied Cr-based DP Sr2CrReO6, previously known to have the highest Tc = 610 K. This paper proposes a theoretical support by Monte Carlo Simulation (MCS) to study the magnetic properties of the diluted DP Sr2CrRexOs1−xO6 doped by Re-substitution. It has been found that the presence although minimal of Os-atoms in the system, is in favor of increasing Tc considerably. At 60% of Os-concentration, a certain competition has been noticed between ferromagnetic double-exchange (DE) and antiferromagnetic super-exchange (SE) interactions. It has been proposed that such a competition occurs at the half-metal-insulator transition due to 5d-band filling. Osmium crystal field effect on Tc, correlated with the Os-concentration in the system, has been also reported.