Complexions and stoichiometry of the 60.8°//[100](011) symmetrical tilt grain boundary in Mg2SiO4 forsterite: a combined empirical potential and first-principles study
| Autor: | Jean Furstoss, Pierre Hirel, Philippe Carrez, Patrick Cordier |
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| Přispěvatelé: | Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-16-IDEX-0004,ULNE,ULNE(2016), European Project: 787198,ERC-2017-ADG,TimeMan(2019), Université de Lille, CNRS, INRAE, ENSCL, Unité Matériaux et Transformations (UMET) - UMR 8207 |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | The American Mineralogist The American Mineralogist, 2022, 107 (11), pp.2034-2043. ⟨10.2138/am-2022-8420⟩ |
| ISSN: | 0003-004X 1945-3027 |
| Popis: | In this work we explore the low-energy complexions of the symmetrical tilt grain boundary (GB) 60.8°//[100](011) in forsterite through molecular dynamics and first principles calculations. Using a conservative sampling, we find six stoichiometric complexions with energies ranging from 0.66 to 1.25 J/m2. We investigate the segregation of MgO vacancy pairs, and find that in most cases it is more favorable for the vacancies to lie within the GBs than in the surrounding crystals, leading to new atomic structures. From these results we infer that at finite temperature when vacancies are present in the system, GBs are likely to absorb them and to be non-stoichiometric. We find many GB complexions containing a free oxygen ion, which may have profound implications for geological processes. |
| Databáze: | OpenAIRE |
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