Selective saturation of paramagnetic defects in electron- and neutron-irradiated GaAs

A comparison of the electron paramagnetic resonance spectra obtained in fast neutron- and electron-irradiated GaAs crystals has confirmed the simultaneous presence of the quadruplet and singlet spectra, ascribed previously to As4+Ga and V2−Ga centers. Only in electron-irradiated material, however, are both signals separated by the selective microwave power saturation of the quadruplet. This apparent disparity is ascribed to a difference in the coupling between the two partners in the As4+Ga-V2−Ga associated complexes.