LDA+U study of ferromagnetism in Ga1-xMnxN.

Structural, electronic and half metallic ferromagnetic properties of Ga1-xMnxN compounds have been studied at dopant concentrations x=0.25, 0.125 and 0.0625 using LDA+U approximation implemented in SIESTA. The calculated results show that Mn doping in GaN induces ferromagnetism and originates a half metallic gap at Fermi level in majority spin channel for all concentrations. Moreover diluted magnetic semiconductor compounds retain half metallic nature at all concentrations with 100% spin polarization at Fermi level (EF). Total magnetic moment of these compounds is due to Mn-3d states and existence of small magnetic moment on Ga and N, non- magnetic atoms, for all doping concentrations is consequence of p-d hybridization of Mn-3d and N-p states. The calculated values of s-d exchange constant Nα and p-d exchange constant Nβ confirms the magnetic character of these compounds. [ABSTRACT FROM AUTHOR]