An investigation on the effect of gamma-irradiation on the optical absorption spectra in Cu(II) doped ammonium Tetrachlorozincate (ATZC) single crystals

Optical transmittance measurements were carried out on Ammonium tetrachlorozincate (ATZC) crystals doped with small concentrations of Cu2+ ions and irradiated with different doses of gamma-radiation. The absorption coefficient (alpha) and the extinction coefficient (K) of unirradiated and irradiated ATZC crystals were calculated. Valued of the allowed indirect optical energy gap (Eg) of ATZC were calculated as a function of gamma-dose. The effect of gamma irradiation is to increase in the absorption coefficient value and to decrease in Eg value. The results could be explained in the fact that gamma irradiation produces defects of ionizing type because of internal irradiation with photon or Compton electrons