Structural, Elastic, Electronic, and Magnetic Properties of a New Full-Heusler Alloy Mn2MgGe: First-Principles Calculations

We present the first-principles calculations of the structural, elastic, electronic, and magnetic properties for a new full-Heusler alloy Mn2MgGe. Both L21 and XA structures are considered for both nonmagnetic and ferromagnetic states. The results show that the XA structure in the ferromagnetic state is the energetically most favorable for the full-Heusler alloy, and exhibits ductile behavior, significant anisotropy, and robust half-metallicity. The total spin moment is 2.000 μB per formula unit in equilibrium state, which follows the Slater-Pauling rule. The spin-up electrons are metallic, whereas the spin-down bands are semiconductor with a gap of 1.086 eV at the equilibrium lattice constant of 6.066 A. Half-metallicity is maintained within the lattice constant range from 5.6 to 6.1 A. Our results indicate that Mn2MgGe is an interesting candidate in the area of spintronics.