Investigations were carried out to study the ferromagnetic properties of transition metal doped wurtzite GaN from first principle calculations using tight binding linear muffin-tin orbital method within the density functional theory. The present calculation revealed ferromagnetism in nickel doped GaN with a magnetic moment of 1.13 μB for 6.25% of Ni doping and 1.32μB for 12.5% of nickel doping, there was a decrease of magnetic moment when two Ni atoms were bonded via nitrogen atom. The Ga vacancy (VGa) induced defect showed ferromagnetic state. Here the magnetic moment arose due to the tetrahedral bonding of three N atoms with the vacancy which was at a distance of 3.689Å and the other N atom which was at a distance of 3.678Å .On the other hand the defect induced by N vacancy (VN) had no effect on magnetic moment and the system showed metallic character. When Ni was introduced into a Ga vacancy (VGa) site, charge transfer occurred from the Ni ‘d’ like band to acceptor level of VGa and formed a strong Ni–N bond. In this Ni–VGa complex with an Ni ion and a Ga defect, the magnetic moment due to N atom was 0.299μB .In case of Ni substitution in Ga site with N vacancy, the system was ferromagnetic with a magnetic moment of 1μB.

Magnetic Properties of Ni Doped Gallium Nitride with Vacancy Induced Defect. S.M.Basha, S.Ramasubramanian, R.Thangavel, M.Rajagopalan, J.Kumar: Journal of Magnetism and Magnetic Materials, 2010, 322[2], 238-41