Abstract
Powders of the B-type synthetic apatite exposed to gamma or ultraviolet irradiation were investigated using EPR spectroscopy. It was shown that ultraviolet irradiation leads to the appearance of the EPR spectrum near g = 2, which is similar to the spectrum observed upon gamma irradiation. The decomposition of the EPR spectra into components and the simulation of the shape of the experimental EPR signals revealed that these signals are associated primarily with two types of CO −2 radicals, namely, the axial CO −2 radicals and the orthorhombic CO −2 radicals. The differences in the shapes of the EPR spectra of the samples exposed to gamma and ultraviolet irradiation were explained by different ratios between the axial and orthorhombic CO −2 radicals. It was established that thermal annealing results in an increase in the relative contribution to the total EPR spectrum. This increase was explained by the transformation of the orthorhombic radicals into the axial radicals.
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Original Russian Text © I.P. Vorona, N.P. Baran, S.S. Ishchenko, V.V. Rudko, L.S. Chumakova, V.Yu. Povarchuk, 2008, published in Fizika Tverdogo Tela, 2008, Vol. 50, No. 10, pp. 1779–1783.
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Vorona, I.P., Baran, N.P., Ishchenko, S.S. et al. CO −2 radicals in synthetic hydroxyapatite. Phys. Solid State 50, 1852–1856 (2008). https://doi.org/10.1134/S1063783408100119
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DOI: https://doi.org/10.1134/S1063783408100119