ELECTRICAL AND OPTICAL STUDIES ON GAMMA-IRRADIATED PURE AND CHROMIUM-CHLORIDE-DOPED POLYVINYL-ALCOHOL

Measurements of optical absorption, electrical conductivity and of the dielectric constant were used to study the changes that occur due to y-radiolysis of pure and CrCl3-doped polyvinyl alcohol (PVA) thin films. Identification of the structure and assignments of energy bands were derived in terms of ligand field theory. Induced changes in the absorbance at 282 and 222 nm bands in pure and doped PVA samples, respectively, appeared to be dose dependent. The direct-current (d.c.) electrical conductivity of the samples was measured in the temperature range 296-433 K, and the results obtained revealed that gamma-irradiation enhances the conductivity. The calculated activation energy in the lower temperature region also proved to be dose dependent. Plots of the dielectric constant, epsilon, against temperature show an interesting behaviour which depends on the dopant concentrations and exposure to gamma-irradiation. The results obtained suggest that these materials may have an application in dosimetry.