GdFe₂ Laves phase intermetallic system under pressure: an ab-initio study

Here we perform abinitio study of Curie temperature T_C under hydrostatic pressure for intermetallic compound GdFe₂. To calculate T_C for GdFe₂ we applied mean-field solution of the Heisenberg model for several magnetic sublattices with DFT/LDA calculated values of necessary exchange interaction integrals and local magnetic moments. To compare with available experimental data pressure values were taken from zero up to about 70 Kbar. It corresponds to 2% compression of the volume of the unit cell. In agreement with experimental data _TC grows under pressure. It was shown that Fe ions magnetic sublattice alone provides only about 75% of the experimental Curie temperature T_C ^exp. Gd sublattice is found to give very weak contribution to the T_C ^exp. Here we show that the missing 25 % of T_C ^exp comes from Fe-Gd exchange pairs. (paper)