Effects of Gamma-Radiation on Alkali Halide Crystals

The radiation effects by 7-rays on the infiared absorption spectra of alkali halide crystals (LiF, KI-Tl, and NaI-TI) have been investigated. In LiF crystal, the 3595 cm'1 band caused by FH•••F anions has vanished completely at 4.4x106 r, but the new ab-sorption bands appeared at around 1950 cm-I. In KI-T1 crystal, the new absorption bands at around 1410, 1370, 888, and 805 cm-1 which should not appear in nominally pure KI crystal have been observed. The absorption bands at around 1370 and 805 cm-1 were decreased and a new induced band at around 1250 cm-1 was enhanced with increasing dosage of 7-rays. Similar spectra are obtained by Nal-TI crystal. On the other hand the data on the pressure dependence of the dielectric constant of NaC1 irradiated with 7-rays are given as a function of hydrostatic pressure from 0 to 5,000 kg/cm2