Stability investigation of a decagonal Al—Cu—Co quasicrystal

作者：Ying He, H. Chen, Xiangchao Meng, S. J. Poon, G. J. Shiflet · 发表于：Philosophical Magazine Letters · 年份：1991 · DOI：10.1080/09500839108205993 · 被引用次数：20 · 研究领域：Quasicrystal Structures and Properties、Mineralogy and Gemology Studies、Microstructure and mechanical properties

The stability of the decagonal phase of Al65Cu15, Co20 (d phase) has been studied through thermal annealing, electron beam irradiation and recovery experiments using X-ray and electron diffraction techniques. Long-term annealing of as-cast and melt-spun samples over the temperature 940 to 550°C did not show a decagonal-to-crystalline phase transformation. Upon electron-beam irradiation, the d phase transformed to a f.c.c. phase with a = 351 Å, and the d phase was recovered by heating the f.c.c. phase to 600°C. A simple cubic (s.c.) phase with a = 2.87 Å was found in thin-film samples slightly off the d phase composition, and it transformed partially to the d phase at 600°C. At high temperature (∼900°C), the d and s.c. coexist in the off-composition thin-film and melt-spun samples. Implications of our results on the stability of decagonal Al—Cu—Co are discussed.