CATION PARTITIONING VERSUS TEMPERATURE IN SPINEL: OPTIMIZATION OF SITE OCCUPANTS
- DSpace Home
- →
- Геология России
- →
- ELibrary
- →
- View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.
dc.contributor.author | Foley J.A. | |
dc.contributor.author | Wright S.E. | |
dc.contributor.author | Hughes J.M. | |
dc.date.accessioned | 2021-03-30T10:40:25Z | |
dc.date.available | 2021-03-30T10:40:25Z | |
dc.date.issued | 2001 | |
dc.identifier | https://www.elibrary.ru/item.asp?id=872449 | |
dc.identifier.citation | Physics and Chemistry of Minerals, 2001, 28, 3, 143-149 | |
dc.identifier.issn | 0342-1791 | |
dc.identifier.uri | https://repository.geologyscience.ru/handle/123456789/27154 | |
dc.description.abstract | Pavese et al. (1999) examined cation partitioning vs. temperature in a synthetic spinel of composition (Mg0.70 Fe0.233+) Al1.97 O4 using structure data obtained from in situ neutron powder diffraction. After imposing assumptions on the site assignment of vacancies and Fe3+ they assigned the remaining cations by applying least-squares minimization to chemical constraints on site-occupancy sums, site-scattering, chemical composition, and thermal expansion of the octahedral site. Their proposed site assignments exhibit a sharp discontinuity in occupancy fractions versus temperature, a necessary consequence of their assumptions on vacancy assignments. In this paper we reexamine the cation partitioning of the same spinel using the constrained least-squares formulation of OccQP (Wright et al. 2000), which optimizes site occupancies without ad hoc assumptions. We obtain strikingly different results, supporting the general view that spinel undergoes a lambda transition at ~1000 K. For all observed parameters, the residuals obtained with the OccQP assignments are lower than those obtained with the Pavese et al. assignments, in some cases by more than 1 order of magnitude. | |
dc.subject | SYNTHETIC SPINELS | |
dc.subject | ORDERING VERSUS TEMPERATURE | |
dc.subject | CONSTRAINED LEAST SQUARES | |
dc.title | CATION PARTITIONING VERSUS TEMPERATURE IN SPINEL: OPTIMIZATION OF SITE OCCUPANTS | |
dc.type | Статья |
Files in this item
Files | Size | Format | View |
---|---|---|---|
There are no files associated with this item. |
This item appears in the following Collection(s)
-
ELibrary
Метаданные публикаций с сайта https://www.elibrary.ru