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

摘要

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 percent and the formation of Mn-N compounds such as Mn_6N_(2.58) and Mn_3N_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.