Structural characteristics and elasticities of coesite and coesite-II at high pressure
Silica, SiO _2 , has attracted significant interest as one of the most important compounds in the fields of condensed-matter physics, materials science, and geoscience etc. Here, we theoretically investigate crystal structural characteristics and elastic properties of coesite and its high-pressure p...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2020-01-01
|
| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/abb0fd |
| _version_ | 1797750371710402560 |
|---|---|
| author | Ye Wu Shengxuan Huang Haijun Huang Xiang Wu Hanyu Liu |
| author_facet | Ye Wu Shengxuan Huang Haijun Huang Xiang Wu Hanyu Liu |
| author_sort | Ye Wu |
| collection | DOAJ |
| description | Silica, SiO _2 , has attracted significant interest as one of the most important compounds in the fields of condensed-matter physics, materials science, and geoscience etc. Here, we theoretically investigate crystal structural characteristics and elastic properties of coesite and its high-pressure polymorph coesite-II at high pressures, which is critical to improve the understanding of densification mechanism of silica at high pressure. The driving mechanism for the pressure-induced transition pathways of coesite comes from both structural features and elastic effect. The phase transition of coesite to cosite-II is triggered by the shortening of Si1–O1 bond distance, and accompanied by elastic instability from a combination of softening elastic constants C _44 and C _46 . The structural modulation of coesite-II along the b -axis direction, as proposed experimentally, results from, on the one hand, the bending of Si2–O15–Si3 angles and shortening of Si5–O4 and Si7–O4 distance with increasing pressure and, on the other hand, elastic softening associated with phonon instability. These results provide key insights into the densification mechanism of silica under high pressure. |
| first_indexed | 2024-03-12T16:31:49Z |
| format | Article |
| id | doaj.art-c12b5acf77a84564bd6cf7731e13afae |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:31:49Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-c12b5acf77a84564bd6cf7731e13afae2023-08-08T15:27:29ZengIOP PublishingNew Journal of Physics1367-26302020-01-0122909304410.1088/1367-2630/abb0fdStructural characteristics and elasticities of coesite and coesite-II at high pressureYe Wu0https://orcid.org/0000-0001-8978-3483Shengxuan Huang1Haijun Huang2Xiang Wu3Hanyu Liu4School of Science, Wuhan University of Technology , Wuhan 430070, People’s Republic of ChinaKey Laboratory of Orogenic Belts and Crustal Evolution, MOE, Peking University and School of Earth and Space Sciences, Peking University , Beijing 100871, People’s Republic of ChinaSchool of Science, Wuhan University of Technology , Wuhan 430070, People’s Republic of ChinaState key laboratory of geological processes and mineral resources, China University of Geosciences (Wuhan) , Wuhan 430074, People’s Republic of ChinaInternational Center for Computational Method and Software, College of Physics, Jilin University , Changchun 130012, People’s Republic of ChinaSilica, SiO _2 , has attracted significant interest as one of the most important compounds in the fields of condensed-matter physics, materials science, and geoscience etc. Here, we theoretically investigate crystal structural characteristics and elastic properties of coesite and its high-pressure polymorph coesite-II at high pressures, which is critical to improve the understanding of densification mechanism of silica at high pressure. The driving mechanism for the pressure-induced transition pathways of coesite comes from both structural features and elastic effect. The phase transition of coesite to cosite-II is triggered by the shortening of Si1–O1 bond distance, and accompanied by elastic instability from a combination of softening elastic constants C _44 and C _46 . The structural modulation of coesite-II along the b -axis direction, as proposed experimentally, results from, on the one hand, the bending of Si2–O15–Si3 angles and shortening of Si5–O4 and Si7–O4 distance with increasing pressure and, on the other hand, elastic softening associated with phonon instability. These results provide key insights into the densification mechanism of silica under high pressure.https://doi.org/10.1088/1367-2630/abb0fdcoesitecrystal structurehigh pressureelasticityfirst-principles calculation |
| spellingShingle | Ye Wu Shengxuan Huang Haijun Huang Xiang Wu Hanyu Liu Structural characteristics and elasticities of coesite and coesite-II at high pressure New Journal of Physics coesite crystal structure high pressure elasticity first-principles calculation |
| title | Structural characteristics and elasticities of coesite and coesite-II at high pressure |
| title_full | Structural characteristics and elasticities of coesite and coesite-II at high pressure |
| title_fullStr | Structural characteristics and elasticities of coesite and coesite-II at high pressure |
| title_full_unstemmed | Structural characteristics and elasticities of coesite and coesite-II at high pressure |
| title_short | Structural characteristics and elasticities of coesite and coesite-II at high pressure |
| title_sort | structural characteristics and elasticities of coesite and coesite ii at high pressure |
| topic | coesite crystal structure high pressure elasticity first-principles calculation |
| url | https://doi.org/10.1088/1367-2630/abb0fd |
| work_keys_str_mv | AT yewu structuralcharacteristicsandelasticitiesofcoesiteandcoesiteiiathighpressure AT shengxuanhuang structuralcharacteristicsandelasticitiesofcoesiteandcoesiteiiathighpressure AT haijunhuang structuralcharacteristicsandelasticitiesofcoesiteandcoesiteiiathighpressure AT xiangwu structuralcharacteristicsandelasticitiesofcoesiteandcoesiteiiathighpressure AT hanyuliu structuralcharacteristicsandelasticitiesofcoesiteandcoesiteiiathighpressure |