Mn impurity in GaN studied by electron paramagnetic resonance

Abstract

We present the results of electron paramagnetic resonance investigations of GaN bulk crystals doped with Mn. The EPR experiment shows the Mn2+ resonance in all the investigated n-type crystals, while in highly resistive samples extra doped with Mg acceptor the Mn2+ resonance decreases. This is a consequence of the location of Mn acceptor level in GaN band gap. The analysis of the spin relaxation times reveals the Korringa scattering as the dominating spin relaxation mechanism in n-type GaN:Mn crystals. The effective exchange constant determined from spin relaxation rate temperature dependence is of the order of 14 meV.