High-pressure phase transformations in carbonates
2010 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 82, no 18, 184115- p.Article in journal (Refereed) Published
High-pressure phase transitions sequences in CaCO3, SrCO3, and BaCO3 are studied by first-principle electronic structure calculations. Each of the carbonates undergoes the aragonite to postaragonite phase transition with pressure in agreement with the experimental observation of Ono et al. However, the postaragonite to post-postaragonite phase transition, predicted by Oganov et al. and later observed in CaCO3, is unlikely to occur in SrCO3 and BaCO3. Hence, the concept that isostructural compounds will exhibit the same type of pressure-induced phase transitions has limitations. A change of the hybridization of the carbon atom from sp(2) to sp(3) within the Pmcn phase occurs in each of compounds, thus the carbonates are likely to transform at very high pressure to structures with tetrahedral CO4-4 carbonate group.
Place, publisher, year, edition, pages
2010. Vol. 82, no 18, 184115- p.
generalized gradient approximation, aragonite plus magnesite, augmented-wave method, earths lower mantle, crystal-structure, high-temperature, caco3, strontianite, transition, stability
IdentifiersURN: urn:nbn:se:kth:diva-27938DOI: 10.1103/PhysRevB.82.184115ISI: 000284462200002ScopusID: 2-s2.0-78649692114OAI: oai:DiVA.org:kth-27938DiVA: diva2:383264
FunderSwedish Research Council
QC 201101042011-01-042011-01-032011-01-04Bibliographically approved