Strain-Induced Neel Temperature Enhancement in Corundum-Type Cr2O3 and Fe2O3

The effect of strain on Neel temperature in corundum-type Cr2O3 and Fe2O3 was theoretically studied. We calculated the exchange coupling constants up to the fifth-nearest neighbors using the first-principles density functional method and evaluated the Neel temperature using Monte Carlo simulation of the classical Heisenberg model. We showed that the Neel temperature is enhanced (decreased) by tensile (compressive) strain along the c-axis. The Neel temperatures of Cr2O3 and Fe2O3 are enhanced more than 20 and 7% by 5% strain of the crystal lattice, respectively. (C) 2013 The Japan Society of Applied Physics