Fluorescence x-ray absorption fine structure study on local structures around Fe atoms heavily doped in GaN by low-temperature molecular-beam epitaxy

A local structural transition in heavily Fe-doped GaN films related to the magnetic properties has been revealed by fluorescence x-ray absorption fine structure (XAFS) analysis. The structural transition is explained (or considered to be induced) by the change in the degree of hybridization between Fe 3d and N 2p states, which can be evaluated by x-ray absorption near edge structure spectra. The XAFS analysis indicates that the present diluted magnetic semiconductor based on GaN can be fabricated by electron cyclotron resonance microwave plasma-assisted low-temperature molecular-beam epitaxy.