Magnetic behavior and Curie temperature of Dy doped MgSe: Ab-initio calculations

In this paper, we have studied the structural, electronic and magnetic properties of Magnesium selenide (MgSe) doped with a rare earth magnetic impurity “Dy” in the zinc blende structure (Mg1−xDyxSe). The ab-initio calculations are performed using the Akai-KKR code, based on the density functional theory. The host compound is a nonmagnetic semiconductor with a gap energy of 1.45 eV. Doping with only 6% of Dy gives MgSe a metallic behavior with a spin polarization of 83% at the Fermi level. In addition, the ferromagnetism is the most stable magnetic phase in the doped system. The Dy impurity contributes with various magnetic moments ranging from 0.23 muB to 0.31 muB for concentrations of 6% and 20% respectively. Besides, Vegard's law is used in order to evaluate the variation of the lattice parameter as a function of Dy concentration. Lastly, the Curie temperature is also calculated, it turns out to be equal to 260 K, which is lower than the room temperature. Doped MgSe is an excellent choice for electronic devices owing to its metallic characteristic below the Tc temperature.