ENDOR study of irradiated tooth enamel
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...
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| Veröffentlicht in: | Semiconductor Physics Quantum Electronics & Optoelectronics |
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| Datum: | 1999 |
| Hauptverfasser: | , , |
| Format: | Artikel |
| Sprache: | Englisch |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
1999
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| Online Zugang: | https://nasplib.isofts.kiev.ua/handle/123456789/117926 |
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Zitieren: | 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. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1862560601579978752 |
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| author | Ishchenko, S. Vorona, I. Okulov, S. |
| author_facet | Ishchenko, S. Vorona, I. Okulov, S. |
| citation_txt | 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. |
| collection | DSpace DC |
| container_title | Semiconductor Physics Quantum Electronics & Optoelectronics |
| 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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| first_indexed | 2025-11-25T23:07:37Z |
| format | Article |
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| id | nasplib_isofts_kiev_ua-123456789-117926 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1560-8034 |
| language | English |
| last_indexed | 2025-11-25T23:07:37Z |
| publishDate | 1999 |
| publisher | Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| record_format | dspace |
| spelling | Ishchenko, S. Vorona, I. Okulov, S. 2017-05-27T16:03:18Z 2017-05-27T16:03:18Z 1999 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 https://nasplib.isofts.kiev.ua/handle/123456789/117926 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. The authors wish to thanks Prof. A.B. Roitsin for consultations on the theory of powder ENDOR and Dr. S.V. Virko for assistance in computer calculations. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics ENDOR study of irradiated tooth enamel Article published earlier |
| spellingShingle | ENDOR study of irradiated tooth enamel Ishchenko, S. Vorona, I. Okulov, S. |
| title | ENDOR study of irradiated tooth enamel |
| title_full | ENDOR study of irradiated tooth enamel |
| title_fullStr | ENDOR study of irradiated tooth enamel |
| title_full_unstemmed | ENDOR study of irradiated tooth enamel |
| title_short | ENDOR study of irradiated tooth enamel |
| title_sort | endor study of irradiated tooth enamel |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/117926 |
| work_keys_str_mv | AT ishchenkos endorstudyofirradiatedtoothenamel AT voronai endorstudyofirradiatedtoothenamel AT okulovs endorstudyofirradiatedtoothenamel |