An Ar-antisite related defect which was produced in n-type samples by 2MeV electron irradiation was investigated by using magnetic circular dichroism of optical absorption, electron paramagnetic resonance, and electron-nuclear double resonance techniques. When compared with other As-antisite related defects, such as EL2, the investigated defect exhibited a reduced hyperfine interaction with the central AsGa atom; 2050MHz, as compared with 2650MHz for EL2. Large super-hyperfine interactions, of the order of 250MHz, with the nearest As neighbor shell were observed. On the basis of the electron paramagnetic resonance lineshape and electron nuclear double resonance data, it was concluded that the defect consisted of an As antisite and a first As shell vacancy.

Optically detected magnetic resonance study of an arsenic-antisite arsenic-vacancy complex in GaAs F.K.Koschnick, K.H.Wietzke, J.M.Spaeth: Physical Review B, 1998, 58[12], 7707-16