Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide Glasses
Glasses with composition of GexSb40-xSe60 (x= 40, 35, 32, 27, 20, 15 at. %) have been synthesized. Neutron and X-ray diffraction techniques were used to study the atomic glassy structure, and Reverse Monte Carlo (RMC) simulations were applied to model the 3-dimensional atomic configurations and thor...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Advances in Condensed Matter Physics |
| Online Access: | http://dx.doi.org/10.1155/2018/7158079 |
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| author | M. Fabian N. Dulgheru K. Antonova A. Szekeres M. Gartner |
| author_facet | M. Fabian N. Dulgheru K. Antonova A. Szekeres M. Gartner |
| author_sort | M. Fabian |
| collection | DOAJ |
| description | Glasses with composition of GexSb40-xSe60 (x= 40, 35, 32, 27, 20, 15 at. %) have been synthesized. Neutron and X-ray diffraction techniques were used to study the atomic glassy structure, and Reverse Monte Carlo (RMC) simulations were applied to model the 3-dimensional atomic configurations and thorough mapping of the atomic parameters, such as first and second neighbour distances, coordination numbers, and bond-angle distributions. The results are explained with formation of GeSe4 and SbSe3 structural units, which correlate with the Ge/Sb ratio. For all the studied compositions, the Ge-Se, Sb-Se, Ge-Ge, and Se-Se bonds are significant. RMC simulations reveal the presence of Ge-Sb and Sb-Sb bonds, being dependent on Ge/Sb ratio. All atomic compositions satisfy formal valence requirements, i.e., Ge is fourfold coordinated, Sb is threefold coordinated, and Se is twofold coordinated. By increasing the Sb content, both the Se-Ge-Se bonds angle of 107±3° and Se-Sb-Se bonds angle of 118±3° decrease, respectively, indicating distortion of the structural units. Far infrared Fourier Transform spectroscopic measurements conducted in the range of 50-450 cm-1 at oblique (75°) incidence radiation have revealed clear dependences of the IR band’s shift and intensity on the glassy composition, showing features around x=27 at.% supporting the topological phase transition to a stable rigid network consisting mainly of SbSe3 pyramidal and GeSe4 tetrahedral clusters. These results are in agreement with the Reverse Monte Carlo models, which define the Ge and Sb environment. |
| format | Article |
| id | doaj-art-3abb00ab07db428eb2c4ed06459c6ea4 |
| institution | Kabale University |
| issn | 1687-8108 1687-8124 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Condensed Matter Physics |
| spelling | doaj-art-3abb00ab07db428eb2c4ed06459c6ea42025-02-03T01:08:49ZengWileyAdvances in Condensed Matter Physics1687-81081687-81242018-01-01201810.1155/2018/71580797158079Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide GlassesM. Fabian0N. Dulgheru1K. Antonova2A. Szekeres3M. Gartner4Centre for Energy Research, Hungarian Academy of Sciences, H-1525 Budapest P.O.B. 49, HungaryInstitute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, RomaniaInstitute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, 1784 Sofia, BulgariaInstitute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, 1784 Sofia, BulgariaInstitute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, RomaniaGlasses with composition of GexSb40-xSe60 (x= 40, 35, 32, 27, 20, 15 at. %) have been synthesized. Neutron and X-ray diffraction techniques were used to study the atomic glassy structure, and Reverse Monte Carlo (RMC) simulations were applied to model the 3-dimensional atomic configurations and thorough mapping of the atomic parameters, such as first and second neighbour distances, coordination numbers, and bond-angle distributions. The results are explained with formation of GeSe4 and SbSe3 structural units, which correlate with the Ge/Sb ratio. For all the studied compositions, the Ge-Se, Sb-Se, Ge-Ge, and Se-Se bonds are significant. RMC simulations reveal the presence of Ge-Sb and Sb-Sb bonds, being dependent on Ge/Sb ratio. All atomic compositions satisfy formal valence requirements, i.e., Ge is fourfold coordinated, Sb is threefold coordinated, and Se is twofold coordinated. By increasing the Sb content, both the Se-Ge-Se bonds angle of 107±3° and Se-Sb-Se bonds angle of 118±3° decrease, respectively, indicating distortion of the structural units. Far infrared Fourier Transform spectroscopic measurements conducted in the range of 50-450 cm-1 at oblique (75°) incidence radiation have revealed clear dependences of the IR band’s shift and intensity on the glassy composition, showing features around x=27 at.% supporting the topological phase transition to a stable rigid network consisting mainly of SbSe3 pyramidal and GeSe4 tetrahedral clusters. These results are in agreement with the Reverse Monte Carlo models, which define the Ge and Sb environment.http://dx.doi.org/10.1155/2018/7158079 |
| spellingShingle | M. Fabian N. Dulgheru K. Antonova A. Szekeres M. Gartner Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide Glasses Advances in Condensed Matter Physics |
| title | Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide Glasses |
| title_full | Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide Glasses |
| title_fullStr | Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide Glasses |
| title_full_unstemmed | Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide Glasses |
| title_short | Investigation of the Atomic Structure of Ge-Sb-Se Chalcogenide Glasses |
| title_sort | investigation of the atomic structure of ge sb se chalcogenide glasses |
| url | http://dx.doi.org/10.1155/2018/7158079 |
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