ORIGINAL ARTICLES ESR and Infrared Studies of Gamma-Irradiated Lead-Phosphate Glasses Doped with MnO 2

M El-Ahdal, M El-Ahdal, E Antar, H Mahmoud, F Ezz-Eldin
2011 Journal of Applied Sciences Research   unpublished
The influence of various gamma-radiation dose on absorptions of PbO-P 2 O 5 + xMnO 2 (0<x<0.15) vitreous system was monitored by means of electron spin resonance (ESR) and infrared (IR) spectroscopy. Electron spin resonance (ESR) of Mn 2+ ions revealed their distribution as different structural units in P 2 O 5 .PbO 2 glass matrices doped with MnO 2. The absorption line at g eff ≈ 2.0 is prevalent in the spectrum and shows the hyperfine structure (hfs) characteristic of the 55 Mn (I=5/2)
more » ... 5 Mn (I=5/2) isotope that is well resolved for samples with x ≤ 0.15 mol%. The ESR and magnetic susceptibility data suggest that in these glasses, the MnO 2 ions exist only in the divalent state; these ions are isolated or participate to dipole-dipole interactions. IR absorption spectra reveal in the undoped and Mn-doped glasses characteristic structural phosphate groups mainly consisting of metaphosphate and pyrophosphate units. Gamma irradiation of the samples is assumed to cause changes in the bond angles or bond lengths of the structural phosphate units within network as evident in the variation of the intensities of the IR bands.
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