ESR AND OPTICAL-ABSORPTION SPECTRA OF CO2-B2O3 AND K2SO4-ZNSO4 GLASSES( IONS IN LIF)

The results of an investigation of the structure of Co2+ ions in xLiF- (100 - x)B2O3 and xK(2)SO(4)-(100 - x)ZnSO4 glasses with 10 less than or equal to x less than or equal to 50 mol% using electron spin resona nce spectroscopy (ESR) and optical absorption techniques are reported. The ESR spectra of Co2+ doped LiF-B2O3 glasses at 4.2 K has a broad a symmetric line at g=4.41+/-0.02 and a broad hump at g=2.30+/-0.05. ESR spectra of Co2+ ions in K2SO4-ZnSO4 glasses at 4.2 K have a single br oad symmetric line at g=4.38+/-0.02. Optical absorption spectra were r ecorded at room temperature. The observed bands were interpreted in te rms of ligand field theory. From the spectral analysis the crystal fie ld parameter (Dq) and the Racah interelectronic repulsion parameters ( B and C) have been evaluated. By correlating the ESR and optical absor ption data, the covalency parameter has been evaluated.