57Fe Mössbauer study of the point defects induced by electron beam irradiation in aluminum containing 100 ppm of57Fe impurities has been presented.57Fe Mössbauer spectra obtained at 10 K just after the electron irradiation at 77 K show satellite lines rising from the defects associated with the57Fe probe atoms in aluminum matrix. The intensity of the satellite line (defect line) abruptly diminished around 20 K. Apparent reduction in the intensity of the defect line is interpreted as a result of the local jump of the probe57Fe atoms in the cage, which consists of six geometrically equivalent mixed-dumbbell positions. The local jump collapses the coherence of the Mössbauer gamma-rays and the time dependent relaxation of the quadrupole interaction occurs.