Previous experimental investigations have only shown, without explanation, that the pre-exponential factor (D0), 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 Auger Electron Spectroscopy (AES) and linear temperature heating. Segregation parameters, including the D0’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 D0 (Sb in Cu(111)) and D0 (Sb in Cu(110)) is explained thermodynamically in terms of entropy change S that is calculated, for the first time, for a Cu(111/110) bi-crystal.
Reference:
Jafta, CJ, Roos, WD, Terblans, JJ, Asante, JKO and Ozoemena, KI. The surface orientation dependence of the pre-exponential factors extracted from the segregation profiles of a Cu(111/110) bi-crystal. Proceedings of SAIP2011, the 56th Annual Conference of the South African Institute of Physics, St George Hotel, Pretoria, 12-15 July 2011
Jafta, C., Roos, W., Terblans, J., Asante, J., & Ozoemena, K. (2011). The surface orientation dependence of the pre-exponential factors extracted from the segregation profiles of a Cu(111/110) bi-crystal. UNISA. http://hdl.handle.net/10204/5683
Jafta, CJ, WD Roos, JJ Terblans, JKO Asante, and KI Ozoemena. "The surface orientation dependence of the pre-exponential factors extracted from the segregation profiles of a Cu(111/110) bi-crystal." (2011): http://hdl.handle.net/10204/5683
Jafta C, Roos W, Terblans J, Asante J, Ozoemena K, The surface orientation dependence of the pre-exponential factors extracted from the segregation profiles of a Cu(111/110) bi-crystal; UNISA; 2011. http://hdl.handle.net/10204/5683 .
ResearchSpace
