Abstract
The influence of neutron irradiation on ultraviolet/visible absorption and thermally stimulated depolarization current in nickel chloride-poly(vinyl alcohol) (PVA) cast films has been investigated. The spectral measurements indicate the responsibility of the Ni2+ ion in its octahedral symmetry. Dopant concentrations higher than 10 wt % Ni Cl-2 are found to make the samples more resistant to a degradation effect caused by neutron irradiation. The thermally stimulated depolarization currents (TSDC) of pure PVA revealed the existence of the glass transition T-g and space charge relaxation peaks, whereas doped-PVA samples show a new sub-T-g relaxation peak. A proposed mechanism is introduced to account for the neutron effects on both glass transition and space charge relaxation peaks. The peak positions, peak currents, and stored charges of the sub-T-g relaxation peak are strongly affected by both the concentration of the dopant and neutron exposure doses. (C) 1993 John Wiley & Sons, Inc.