Local structure around Mn atoms in cubic (Ga,Mn)N thin films probed by fluorescence extended x-ray absorption fine structure

摘要

The local structures of Mn atoms incorporated in zinc-blende (Ga,Mn)N thin films have been investigated by fluorescence extended x-ray absorption fine structure analysis (EXAFS). The EXAFS results provide direct evidence for the substitution of the majority of Mn atoms in Ga sites of GaN at 2.5% doping. On the other hand, the simulation result of 10% doped (Ga,Mn)N shows that secondary phases—Mn clusters—are formed. The long-range-order crystal structures of (Ga,Mn)N are also studied by x-ray diffraction. The broadening of rocking curve of 10% doped (Ga,Mn)N is attributed to the existence of mosaic block, which resulted from the earlier mentioned secondary phases. How Mn dopants affect the properties of GaN films is discussed as well.