EPR and Optical Absorption Spectral Investigations of Cu2+ in Bi2O3-ZnO-B2O3-Li2O Glasses

Abstract EN

Electron paramagnetic resonance and optical absorption studies of Bi2O3-ZnO-B2O3-Li2O glasses were made by introducing Cu2+ as spin probe.

The EPR spectra of Cu2+ in all the glass samples recorded in the X-band frequency have similar spectral features.

The variation in glass composition influences the spin Hamiltonian parameters calculated from the spectra.

The spin Hamiltonian parameters indicate that the Cu2+ ions are coordinated with six ligand atoms in a distorted octahedron elongated along one of the axes and the ground state of the Cu2+ is dx2−y2 orbital.

The optical absorption spectra exhibited a broad band corresponding to d-d transition bands of Cu2+ ion.

The values of bonding parameters indicate a covalent nature for the in-plane σ bonding and pure ionic nature for the in-plane and out-of-plane π bonding.

The theoretical optical basicity parameter values were evaluated, and it was observed that the value of Γσ increases whereas Γπ decreases with the increase in optical basicity.