Electron paramagnetic resonance and optical absorption studies of Cu2+ probe in Li2O-Bi2O3-As2O3-B2O3 glasses

Copper doped Li2O-Bi2O3-As2O3-B2O3 glasses were prepared by the conventional melt quenching process. The room temperature Electron paramagnetic resonance (EPR) and Optical absorption studies of the present glasses were made by introducing copper ion (Cu2+) as the spin probe. All the glass samples of the EPR spectra recorded at 8-12GHz (X-band) frequencies have alike spectral features. The spin-Hamiltonian parameters were calculated. These values indicate that the ground state of Cu2+ ion is dx2- y2 and the site symmetry around copper ions is tetragonally distorted octahedral. The optical absorption spectra exhibited a broad band corresponding to the d-d transition bands of Cu2+ ion. By correlating the EPR and optical absorption spectral data, the nature of the in-plane σ bonding between Cu2+ ion and the ligands is estimated.