J. Phys. IV France 11 (2001) Pr8-31-Pr8-35
Precursor phenomenon on TiNi R phase transformation by X-ray diffractionT. Ohba1, 2 and Y. Miyata3, 4
1 Department of Materials Science and Engineering, Teikyo University, Utsunomiya 320-8551, Japan
2 Department of Materials Science, Shimane University, Nishikawatsu, Matsue 690-8504, Japan.
3 Department of Environmental and Material Engineering, Teikyo University of Science and Technology, Uenohara, Yamanashi 409-0193, Japan
4 The Graduate University of Advanced Studies, Tsukuba 305-0801, Japan.
TiNi alloy system has been widely used for industrial application and fundamental research. Many studies were performed under circumstance that R phase was not certainly established. Recently R phase was established and structure of R phase was determined. Present study reports diffuse scattering study as a precursor phenomenon to R-phase by using four-circle diffractometer under circumstance that the structure was determined. Diffuse scattering was observed around 1/3 of [1 -1 0]* incommensurate position at various temperatures in parent phase. Shift from commensurate position broke symmetry and temperature dependence looked random. FWHM of 1/3 reflections and integrated intensities were measured also in parent phase. FWHM decreased and integrated intensities increased with approaching transformation temperature.
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