ENDOR study of irradiated tooth enamel
Vernadsky National Library of Ukraine
Переглянути архів Інформація| Поле | Співвідношення | |
| Title |
ENDOR study of irradiated tooth enamel
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| Creator |
Ishchenko, S.
Vorona, I. Okulov, S. |
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| Description |
γ- and x-irradiated tooth enamel has been studied by EPR and ENDOR. Radiation-induced EPR spectrum of tooth enamel was found to be a superposition of signals with dominant contribution determined by CO₂- radicals. Two types of these radicals were observed: ordered and disordered centers. EPR spectra of both CO₂- centers are described by axial g-tensor with g = 1.9975 and g ⊥= 2.0021 with g || c. The ENDOR spectrum of unannealed enamel powder consists of a singlet at Larmor frequency of ³¹P nuclei and doublet at Larmor frequency of ¹H nuclei. Samples annealing at T = 200-250 ⁰C resulted in the destruction of disordered centers and appearence of superhyperfine structure of ENDOR spectra. Its analysis with advanced the powder ENDOR theory allows to determine the superhyperfine constants and to find for the first time that the ordered CO₂- radical is located in B sites (phosphorous position) of bioapatite lattice. This substitution is accompanied by the shift of the nuclei of the first ³¹P shell towards the defects by 0.04 nm and the formation of the OH vacancy in the nearest radical surroundings.
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| Date |
2017-05-27T16:03:18Z
2017-05-27T16:03:18Z 1999 |
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| Type |
Article
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| Identifier |
ENDOR study of irradiated tooth enamel / S. Ishchenko, I. Vorona, S. Okulov // Semiconductor Physics Quantum Electronics & Optoelectronics. — 1999. — Т. 2, № 1. — С. 84-92. — Бібліогр.: 29 назв. — англ.
1560-8034 PACS 61.72; 76.30; 76.70 http://dspace.nbuv.gov.ua/handle/123456789/117926 |
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| Language |
en
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| Relation |
Semiconductor Physics Quantum Electronics & Optoelectronics
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| Publisher |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
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