Skip to main content
Kent Academic Repository

Crystal morphology and surface structures of orthorhombic MgSiO3 in the presence of divalent impurity ions

Alfredsson, Maria, Cora, Furio, Brodholt, John P., Parker, Steve C., Price, G. David (2005) Crystal morphology and surface structures of orthorhombic MgSiO3 in the presence of divalent impurity ions. Physics and Chemistry of Minerals, 32 (5-6). pp. 379-387. ISSN 0342-1791. (doi:10.1007/s00269-005-0009-2) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:4763)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
Official URL:
http://dx.doi.org/10.1007/s00269-005-0009-2

Abstract

Many rheological and transport properties of rocks are determined by the grain boundary structures of their constituent minerals. These grain boundaries often also hold a high concentration of dopant ions. Here, as a first step towards modelling the transport and rheological behaviour of the lower mantle, we report the results of lattice static simulations on the surface structures of Fe2+ and Ca2+- doped orthorhombic MgSiO3-perovskite. For all the surfaces we studied, the energies of the doped structures are lowered, sometimes by more than 1 J/m(2), with respect to the pure surfaces. From our calculated crystal morphologies, we predict that the grains become more tabular as the concentration of Fe2+ ions increases, while under equilibrium conditions the grains are cubic. By calculating the replacement energies of Mg2+ by Fe2+ and Ca2+ ions in the six outermost surface layers, we conclude that these divalent ions would tend to segregate onto the crystal surfaces. We suggest, therefore, that the grain boundary structure and rheology of MgSiO3- perovskite dominated rocks will be strongly affected by the presence of minor elements in the lower mantle.

Item Type: Article
DOI/Identification number: 10.1007/s00269-005-0009-2
Additional information: ISI Document Delivery No.: 971GR Times Cited: 2 Cited Reference Count: 49
Uncontrolled keywords: mantle rehology crystal shape perovskite simulation MAGNESIUM-SILICATE PEROVSKITE EARTHS LOWER MANTLE TRANSMISSION ELECTRON-MICROSCOPY COMPUTER-SIMULATION ATOMISTIC SIMULATION IRON DIFFUSION PRESSURE SRTIO3 MG
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Maria Alfredsson
Date Deposited: 02 Sep 2008 20:39 UTC
Last Modified: 16 Nov 2021 09:43 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/4763 (The current URI for this page, for reference purposes)

University of Kent Author Information

  • Depositors only (login required):

Total unique views for this document in KAR since July 2020. For more details click on the image.