Tuning the Curie temperature of FeCo compounds by tetragonal distortion

A. Jakobsson^1,2, E. Şaşıoğlu^{1, a)}, Ph. Mavropoulos¹, M. Ležaić¹, B. Sanyal², G. Bihlmayer¹, and S. Blügel¹

• ¹Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
• ²Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
• ^a)Electronic mail: e.sasioglu@fz-juelich.de

Abstract

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 TC. The TC monotonically decreases from 1575 K (for c/a=1) to 940 K (for c/a=2⎯⎯√). We find that the nearest neighbor Fe-Co exchange interaction is sufficient to explain the c/a behavior of the TC. 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.

https://sci-hub.tw/https://aip.scitation.org/doi/10.1063/1.4819773