EPR and Optical Absorption Studies of Cu2+ in Boro-Arsenate Glasses

Electron paramagnetic resonance (EPR) and optical absorption studies of xMgO- (25-x) Li2O-50B2O3-25As2O3 glasses were made by introducing Cu2+ as a spin probe. The EPR spectra of all the glass samples recorded at X-band frequencies have similar spectral features. The Cu2+ ions are in well-defined axial sites, but subjected to small distortion leading to the broadening of the spectra. The spin-Hamiltonian parameter values indicate that the ground state of Cu2+ is dx2- y2 and the site symmetry around Cu2+ ions is tetragonal distorted octahedral. The optical absorption spectra exhibited a broadba...