Combining density-functional theory calculations with a classical Monte Carlo method, we show that for B2-type FeCo compounds, tetragonal distortion gives rise to a strong reduction of the Curie temperature T-C. The T-C monotonically decreases from 1575K (for c/a = 1) to 940K (for c/a = root 2). We find that the nearest neighbor Fe-Co exchange interaction is sufficient to explain the c/a behavior of the T-C. Combination of high magnetocrystalline anisotropy energy with a moderate TC value suggests tetragonal FeCo grown on the Rh substrate with c/a = 1.24 to be a promising material for heat-assisted magnetic recording applications. (C) 2013 AIP Publishing LLC.
Department of Physics National and Kapodistrian University of Athens University Campus GR-157 84 Zografou, Athens