Palladium in GaN: A 4d metal ordering ferromagnetically in a semiconductor

Abstract

It is shown that a 4d metal (palladium) orders ferromagnetically in GaN, forming a dilute magnetic semiconductor. The ferromagnetic ordering occurs despite Pd being nonmagnetic in its natural phase. Pd0.0625 Ga0.9375 N is shown to possess a magnetic moment of 1.3 μB per supercell, with a spin-polarized impurity band in the GaN band gap and the Fermi level lying within this band. The impurity band is shown to arise from the hybridization of the Pd 4d level with N 2p states. Though the largest experimental and theoretical focus up to now has been on 3d metals such as Mn in III-V and II-VI semiconductors, the results presented here show that 4d metals such as palladium, may also be considered as candidates for ferromagnetic dopants in semiconductors. This broadens the range of dopants which may be taken into account in attempts to overcome technological and other barriers related to the dopants used presently to obtain magnetically ordered semiconductors for potential spintronic applications. © 2005 The American Physical Society.