A first-principles study of elastic, magnetic, and structural properties of PrX2 (X=Fe, Mn, Co) compounds

The elastic, magnetic, and structural properties of PrX2 (X=Fe, Mn, Co) alloys, of the cubic Laves structure (MgCu2), have been evaluated by first-principles density functional theory using both local spin density (LSDA) and generalized gradient (GGA) approximations. The lattice constant, magnetic moment, density of states, band structure, bulk modulus and its first pressure derivative are calculated. At zero pressure, the total magnetic moments of PrFe2, PrCo2, and PrMn2 using GGA are 4.515, 1.05, and 4.79 µB respectively. The bulk moduli using LSDA are higher than those using GGA approximation. The evaluated Bulk moduli of PrFe2, PrMn2 and PrCo2 using GGA approximation are 48.1, 42.98, and 72.23 GPa respectively. The lattice constant and magnetic moment of PrFe2 using GGA approximation are 7.2 Ǻ and 4.51 µB respectively in good agreement with experimental results.