Evidence of Mn Occupation of Ga Site in Ferromagnetic (Ga, Mn)N Semiconductor Observed by EXAFS

Abstract

The local structure of Mn impurities in a ferromagnetic (Ga, Mn)N semiconductor was investigated using extended X-ray absorption fine structure (EXAFS). The ferromagnetic signal increased and maintained up to room temperature as N ions were implanted into Mn-implanted GaN. The X-ray results showed that Mn ions occupied Ga sites to form (Ga, Mn)N semiconductor. The Mn concentration occupying Ga sites increased from 2.5 to 3.8% and the formation of Mn-N compounds such as Mn 6 N 2 . 5 8 and Mn 3 N 2 was prohibited by implanting N atoms. As a result, the N-vacancies reduced and net hole concentration increased, resulting in the enhancement of ferromagnetic property.