Optical properties of PVA doped with CoCl2

ABSTRACT

Optical absorption measurements in the spectral range 4000-50000 cm[-1], were performed on cast thin films of polyvinyl alcohol[PVA] and its composites with cobalt chloride [CoCl [2]. Identification of the structure and assignments of energy bands have been derived in terms of the ligand field theory. A mechanism based on the equilibrium between six-coordinated and four- coordinated symmetry is proposed to account for the obtained spectra. Such equilibrium is attributed to a small difference between the stabilization energies, and the symmetry is found to be altered with cobalt chloride concentrations