Fundamental study on growth and structure of low-dimensional memory alloy.

In order to clarify the structure of an ultrafine memory alloy, an InTl all oy was evaporated by the gas evaporation method and studied by electron mic roscopy. It became evident that two phases? the face-centered cubic (FCC) a nd face-centered tetragonal (FCT) were produced. The surfaces of some spher ical particles were composed of the FCC structure which is a high-temperatu re phase, and the inner parts of the particles were composed of the FCT str ucture. These results have been discussed as being due to the difference in cooling velocity between the inner and surface regions of a particle. In t he present study, In-rich phases were formed and it was evident that these phases appear with the increment of heat cycles. The degradation of the nat ure of the memory alloy has been discussed as being; due to the production of the new In-rich phases.