IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Monday Sessions
       Session SS2-MoP

Paper SS2-MoP4
In-Situ X-Ray Reflectometry of the Martensitic Transformation of AuCd Alloys

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Surfaces and Interfaces Poster Session
Presenter: H. Shimazu, Kwansei Gakuin University, Japan
Authors: H. Shimazu, Kwansei Gakuin University, Japan
S. Shibata, Kwansei Gakuin University, Japan
S. Doi, Kwansei Gakuin University, Japan
I. Takahashi, Kwansei Gakuin University, Japan
T. Ohba, Shimane University, Japan
Correspondent: Click to Email
Numerous works have been dedicated to the study of meaning of surfaces for bulk phase transitions. For second order transitions, importance of the dimensionality has been understood thoroughly. Thus, an answer for this issue might have been obtained. Compared to such a situation, we must admit that many phenomena at the surfaces for first order phase transitions have not fully been understood. Especially, peculiarity of nucleation and evolution of domains at the surface triggered by the first order bulk transition remain unveiled, although those in bulk have been investigated. The martensitic transformation is a first order phase transition, responsible for shape-memory effects. In a low temperature phase, bulk domains called "variants" appear. On the other hand, the surface exhibits a morphological change (surface relief). Many people consider that the surface relief is a mere termination of the bulk variants. If they are correct, the evolution of the surface relief may start simultaneously as the variants start to evolve. However, as far as the authors' knowledge, there is no accepted study on the relationship between nucleation of the surface relief and that of the bulk variants. In the present paper, we focus on in-situ observations about the surface relief and the micro-variants in the vicinity of martensitic transformations of AuCd alloys: We observed the surface relief by X-ray reflectivity, whereas Bragg reflection gave information on bulk variants.@footnote 1@ An image plate detector was adopted with an X-ray camera.@footnote 2@ Our study revealed peculiar properties on the evolution of the surface relief. They indicated that the surface plays an intrinsic role at the first stage of the martensitic transformation. An aging effect was also detected in the surface diffraction. @FootnoteText@ @footnote 1@ S. Doi and I. Takahashi; Philosophical Magazine A, 80(2000) 1889-1899. @footnote 2@ S. Shibata, S. Doi and I. Takahashi; to be published in Surface Science (2001).