SAIP 2011 Support
The Surface Orientation Dependence of the Pre-Exponential Factors Extracted from the Segregation Profiles of a Cu(111/110) Bi-crystal
Presented by Mr. Charl JAFTA on 13 Jul 2011 from 17:00 to 19:00
Type: Poster Presentation
Track: Track A - Condensed Matter Physics and Material Science
<p>Previous experimental investigations have only shown, without explanation, that the pre-exponential factor (D<sub>0</sub>), in the diffusion coefficient of Sb segregating in Cu, is dependent on the surface orientation of a crystal. In this study, the surface concentration of Sb in a Sb doped Cu(111/110) bi-crystal was measured using a method combining AES and linear temperature heating. Segregation parameters, including the D<sub>0</sub>’s are extracted from the experimental data of surface concentration versus temperature using the modified Darken model. The difference in the two pre-exponential factors D<sub>0</sub> (Sb in Cu(111)) and D<sub>0</sub> (Sb in Cu(110)) is explained thermodynamically in terms of entropy change ΔS that is calculated, for the first time, for a Cu(111/110) bi-crystal.
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- Prof. Wiets ROOS Physics Department, University of the Free State
- Prof. Jacobus TERBLANS Physics Department, University of the Free State
- Dr. Joseph ASANTE Physics Department, Tshwane University of Technology
- Prof. Kenneth OZOEMENA Energy and Processes Unit, CSIR