In this work, we present a study of the effect of γ particles radiation in n type gallium arsenide (GaAs) doped with silicon (SiGa ). For this, we have irradiated samples of GaAs doped with 1015cm-3 and 1016cm-3 of SiGa at different fluencies of γ radiation. We have used photoluminescence (PL) measurement at 8.8K to identify defects induced by γ radiation in these samples. We found that this type of radiation induces the gallium vacancy VGa in GaAs and causes the transfer of the silicone impurity from Ga site to As site. These two defects are displacement damages created by γ radiation and are the same of displacement damages created by the other type of radiation (charged particles and neutral particles). The difference between the effect of particles is the introduction rate b of the defect. Then, we found that b or γ particles is ten times weaker than 7MeV electron particles. γ ray are photons, so they can’t interact with GaAs atoms to product displacement damages by Rutherford diffusion (charged particles) or diffusion from hard spheres model (neutral particles). We suggest that recoil electrons produced in GaAs by photoelectric effect and Compton effect are responsible to the creation of these displacement damages. Indeed, these electrons have enough energy (~ 1 MeV) to product the same damages.