Influence of pressure on dislocation, disclination, and generalized-disclination structures of a {310}/[001] tilt grain boundary in MgO. Issue 20 (21st October 2016)

• Record Type: Journal Article
• Authors: Sun, Xiao-Yu; Taupin, Vincent; Cordier, Patrick; Fressengeas, Claude; Karki, Bijaya B.
• Is Part Of: Journal of materials research. Volume 31:Issue 20(2016)
• Page Start: 3108
• Page End: 3114
• Publication Date: 2016-10-21
• Subjects: grain boundary, -- MgO, -- dislocation, -- generalized-disclination, -- continuum mechanics, -- atomistic simulations; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1557/jmr.2016.346
• Languages: English
• ISSNs: 0884-2914

Abstract

Abstract: Abstract : Due to gravitational self-compression, the pressure in planetary interiors can reach millions of times the atmospheric pressure. Such high pressure has a significant influence on their rheology. In the present paper, we focus on how pressure in the range of the Earth's lower mantle may influence the structure of a MgO {310}/[001] tilt boundary. The defected structure of the grain boundary (GB) will be described through its dislocation, disclination, and generalized-disclination (g-disclination) density fields. At first, the strain and rotation fields in the boundary area at different pressures are derived from the discrete atomic positions simulated by first-principles calculations. For each pressure, the discontinuities of displacement, rotation, and strain in the boundary area are continuously rendered by dislocation, disclination, and g-disclination density fields, respectively. These density fields measured at different pressures are compared to provide understanding on how pressure does influence the GB structures in Earth materials.