Phase transformation induced by irradiating an Al<sub>62</sub>Cu<sub>25.5</sub>Fe<sub>12.5</sub> icosahedral quasicrystal
Renhui Wang; Xiangxiu Yang; H Takahashi; S Ohnuki; Renhui Wang; Dept. of Phys., Wuhan Univ., China; Xiangxiu Yang; Dept. of Phys., Wuhan Univ., China; H Takahashi; Dept. of Phys., Wuhan Univ., China; S Ohnuki; Dept. of Phys., Wuhan Univ., China
Журнал:
Journal of Physics: Condensed Matter
Дата:
1995-03-06
Аннотация:
The irradiation effect of the Al<sub>62</sub>Cu<sub>25.5</sub>Fe<sub>12.5</sub> icosahedral quasicrystal (IQC) induced by 120 keV Ar ions and 1 MeV electrons has been studied in situ using high-voltage electron microscope-ion accelerator dual-irradiation facilities. The effect is dose and temperature dependent and we can define three critical temperatures T<sub>c</sub>, T<sub>d</sub> and T<sub>p</sub>. When irradiated at T<T<sub>c</sub> the IQC is transformed into a crystalline microtwin oriented according to icosahedral symmetry. When T>T<sub>c</sub>, the IQC remains an IQC but with a higher (when T>T<sub>d</sub>) or lower (when T<T<sub>d</sub>) degree of perfection. The planar defects originally existing in the Al<sub>62</sub>Cu<sub>25.5</sub>Fe<sub>12.5</sub> IQC foils are stable when T>T<sub>p</sub> but disappear when T<T<sub>p</sub>. For the Al<sub>62</sub>Cu<sub>25.5</sub>Fe<sub>12.5</sub> IQC, we found that T<sub>c</sub> approximately=400 K, T<sub>d</sub> approximately=450 K (for 1 MeV electrons) or 550 K (for 120 keV Ar ions) and T<sub>p</sub> approximately=600 K.
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