XRD Investigation of SHS-Produced Boron Carbide
Boron carbide with compositions corresponding to the homogeneity region in its phase diagram was obtained by self-propagating high temperature synthesis (SHS). The received samples were characterized by X-ray diffraction (XRD) analysis, lattice parameters and half-width of reflections have been inve...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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al-Farabi Kazakh National University
2013-05-01
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| Series: | Eurasian Chemico-Technological Journal |
| Online Access: | http://ect-journal.kz/index.php/ectj/article/view/257 |
| _version_ | 1818927343515729920 |
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| author | I. D. Kovalev V. I. Ponomarev V. I. Vershinnikov S. V. Konovalikhin |
| author_facet | I. D. Kovalev V. I. Ponomarev V. I. Vershinnikov S. V. Konovalikhin |
| author_sort | I. D. Kovalev |
| collection | DOAJ |
| description | Boron carbide with compositions corresponding to the homogeneity region in its phase diagram was obtained by self-propagating high temperature synthesis (SHS). The received samples were characterized by X-ray diffraction (XRD) analysis, lattice parameters and half-width of reflections have been investigated. The lattice parameters of boron carbide reported in the literature exhibit a too wide spread in their values for equal carbon content. It is unusually for covalent compounds such as boron carbide which has strong chemical bonds. The largest spread in lattice parameters was observed at 13.2 % (atomic) of carbon in boron carbide. In other hand, for SHS-produced samples the spread was minimal. Using XRD analysis cell prameters of boron carbide in our experiments was found to depend on carbon concentration in non-linear way. Lattice parameter was found to reach the unusually high value of 12.31 Å. The half-widths of boron carbide diffraction lines were found to depend on carbon concentration and reach their maximum values at 13.2 atomic % of carbon when the lattice is most disordered. The structure analysis allows to associate it with the process of crystal structure ordering caused by replacement of boron atoms by carbon ones during formation of boron carbide structure. The carbon atoms can be incorporated into different positions in both the linear groups and the icosahedra. In other words, some certain composition can correspond to different structure. Therefore, both experimental data and crystal-chemical considerations allow to conclude the possibility of different kinds of ordering in boron carbide structure, resulting in instability of lattice parameters and consequently in properties. |
| first_indexed | 2024-12-20T03:11:30Z |
| format | Article |
| id | doaj.art-ce5c770baaf44047bb07579336889fac |
| institution | Directory Open Access Journal |
| issn | 1562-3920 2522-4867 |
| language | English |
| last_indexed | 2024-12-20T03:11:30Z |
| publishDate | 2013-05-01 |
| publisher | al-Farabi Kazakh National University |
| record_format | Article |
| series | Eurasian Chemico-Technological Journal |
| spelling | doaj.art-ce5c770baaf44047bb07579336889fac2022-12-21T19:55:27Zengal-Farabi Kazakh National UniversityEurasian Chemico-Technological Journal1562-39202522-48672013-05-0115210711010.18321/ectj147257XRD Investigation of SHS-Produced Boron CarbideI. D. Kovalev0V. I. Ponomarev1V. I. Vershinnikov2S. V. Konovalikhin3Russian Academy of Sciences Institute of Structural Macrokinetics and Materials Science Academician Osipyan str., 8, Chernogolovka, Moscow Region, 142432, RussiaRussian Academy of Sciences Institute of Structural Macrokinetics and Materials Science Academician Osipyan str., 8, Chernogolovka, Moscow Region, 142432, RussiaRussian Academy of Sciences Institute of Structural Macrokinetics and Materials Science Academician Osipyan str., 8, Chernogolovka, Moscow Region, 142432, RussiaRussian Academy of Sciences Institute of Structural Macrokinetics and Materials Science Academician Osipyan str., 8, Chernogolovka, Moscow Region, 142432, RussiaBoron carbide with compositions corresponding to the homogeneity region in its phase diagram was obtained by self-propagating high temperature synthesis (SHS). The received samples were characterized by X-ray diffraction (XRD) analysis, lattice parameters and half-width of reflections have been investigated. The lattice parameters of boron carbide reported in the literature exhibit a too wide spread in their values for equal carbon content. It is unusually for covalent compounds such as boron carbide which has strong chemical bonds. The largest spread in lattice parameters was observed at 13.2 % (atomic) of carbon in boron carbide. In other hand, for SHS-produced samples the spread was minimal. Using XRD analysis cell prameters of boron carbide in our experiments was found to depend on carbon concentration in non-linear way. Lattice parameter was found to reach the unusually high value of 12.31 Å. The half-widths of boron carbide diffraction lines were found to depend on carbon concentration and reach their maximum values at 13.2 atomic % of carbon when the lattice is most disordered. The structure analysis allows to associate it with the process of crystal structure ordering caused by replacement of boron atoms by carbon ones during formation of boron carbide structure. The carbon atoms can be incorporated into different positions in both the linear groups and the icosahedra. In other words, some certain composition can correspond to different structure. Therefore, both experimental data and crystal-chemical considerations allow to conclude the possibility of different kinds of ordering in boron carbide structure, resulting in instability of lattice parameters and consequently in properties.http://ect-journal.kz/index.php/ectj/article/view/257 |
| spellingShingle | I. D. Kovalev V. I. Ponomarev V. I. Vershinnikov S. V. Konovalikhin XRD Investigation of SHS-Produced Boron Carbide Eurasian Chemico-Technological Journal |
| title | XRD Investigation of SHS-Produced Boron Carbide |
| title_full | XRD Investigation of SHS-Produced Boron Carbide |
| title_fullStr | XRD Investigation of SHS-Produced Boron Carbide |
| title_full_unstemmed | XRD Investigation of SHS-Produced Boron Carbide |
| title_short | XRD Investigation of SHS-Produced Boron Carbide |
| title_sort | xrd investigation of shs produced boron carbide |
| url | http://ect-journal.kz/index.php/ectj/article/view/257 |
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