Electron paramagnetic resonance and optical absorption studies of Fe(III) ions in alkali barium borate glasses
1998; Elsevier BV; Volume: 10; Issue: 2 Linguagem: Inglês
10.1016/s0925-3467(97)00167-5
ISSN1873-1252
AutoresR.P.S. Chakradhar, Ayaluru Murali, J.L. Rao,
Tópico(s)Mineralogy and Gemology Studies
ResumoElectron paramagnetic resonance (EPR) and optical absorption studies of Fe(III) ions doped in 20 M2O+(25−x) BaO+55B2O3+xFe2O3 (M=Li, Na or K, 0.25≤x≤10) glasses were carried out. The EPR spectra have resonances at g=10±0.5, g=6.4±0.1, g=4.2±0.1 and g=2.0±0.1. The EPR spectra of x=0.5 mol% of Fe2O3 in sodium–barium borate glass sample was studied at various temperatures. The linewidths were found to be unaffected by temperature changes, while the intensity increases with decrease in temperature. From the concentration dependence of the g=4.2 and g=2.0 resonances in sodium–barium borate glasses it was observed that clusters of iron are formed for Fe2O3 contents >3 mol%. The optical absorption spectrum of Fe(III) ions in such a glass exhibits six bands characteristic of Fe(III) ions in octahedral symmetry. From the analysis of the bands, the crystal-field parameter Dq and the Racah interelectronic repulsion parameters B and C were estimated.
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