Ab initio study of magnetic and structural properties of Fe-Ga alloys

The structural and magnetic properties for a series of Fe 100-x Ga x alloys (x = 18 – 30 at.%) are studied in the framework of first-principles calculations and Monte Carlo simulations. The both, general gradient approximation and local density approximation are considered for the exchange-correlation functional. The ground state ab initio calculations are performed for both D0 3 and L1 2 crystal structures. It is shown that for general gradient approximation, the optimized lattice parameters and total magnetic moments are found in the better agreement with experimental ones. Using the calculated exchange coupling constants for studied compositions, Curie temperatures are estimated by means of Monte Carlo simulations of Heisenberg Hamiltonian.