Electron paramagnetic resonance and optical absorption studies of Cu2+ ion doped polyvinyl alcohol films

Electron paramagnetic resonance (EPR) and optical absorption studies have been carried out on Cu2+ ions doped in polyvinyl alcohol films (PVA). EPR spectrum at room temperature exhibits hyperfine structure characteristic of Cu2+ ions in tetragonal symmetry. The EPR spectra have also been recorded at various temperatures. The number of spins participating in the resonanco, is measured as a function of temperature and the activation energy is calculated. The paramagnetic susceptibility (X) is calculated from the EPR lata at various temperatures and the Curie constant is evaluated from 1/chi versus T graph. The optical absorption spectrum exhibits a broad band which has been assigned to the transition B-2(1g) -> B-2(2g). (c) 2006 Elsevier B.V. All rights reserved.