EPR and Optical Absorption by Cu2+ ions in ZnO-Li2O-Na2O-K2O-B2O3 Glasses

Electron Paramagnetic Resonance (EPR) studies at room temperature in the x-band frequencies on xZnO-10Li(2)O-10Na(2)O-10K(2)O-(69-x)B2O3-1CuO (x=0,2,4,6 and 8 mole%) glass systems were reported. The non-linear variation of spin-Hamiltonian parameters with ZnO content indicated the change in the ligand field strength around Cu2+ ions in the host glass. The ground state of Cu2+ ions in the glass is designated as d(x)(2)-(2)(y) orbital (2 B1g) while the observed symmetry around it is tetragonally distorted octahedral. The molecular orbital coefficients alpha(2), beta(2) and beta(2)(1) are evaluated for Cu2+ doped samples. The non-linear variation in the values of parameters indicated mixed alkali effect in the glasses.