ELECTRON-PARAMAGNETIC RESONANCE AND OPTICAL-ABSORPTION SPECTRA OF MN2+ IONS IN ALKALI ZINC BOROSULFATE GLASSES

Electron paramagnetic resonance (EPR) and optical absorption studies have been made for Mn2+ ions in alkali zinc borosulphate (R2SO4.B2O3.ZnSO4; R = Li, Na, K or Cs) glasses. A six-line hyperfine structure spectrum centered at g = 2.005 has been observed in the EPR spectra for all these glasses, at various temperatures (123-423 K) for R = Li. It is observed that the linewidths of the spectrum are independent of the temperature between 123 and 423 K, whereas the EPR intensities decrease with increasing temperature. The optical absorption spectra of Mn2+ ions in the Li glass at 303 K show six bands characteristic of Mn2+ ions in octahedral symmetry. The crystal field parameter D(q) and the Racah interelectronic-repulsion parameters B and C have been evaluated.