Direct observation of the alpha-epsilon transition in shock-compressed iron via nanosecond x-ray diffraction.
نویسندگان
چکیده
In situ x-ray diffraction studies of iron under shock conditions confirm unambiguously a phase change from the bcc (alpha) to hcp (epsilon) structure. Previous identification of this transition in shock-loaded iron has been inferred from the correlation between shock-wave-profile analyses and static high-pressure x-ray measurements. This correlation is intrinsically limited because dynamic loading can markedly affect the structural modifications of solids. The in situ measurements are consistent with a uniaxial collapse along the [001] direction and shuffling of alternate (110) planes of atoms, and are in good agreement with large-scale nonequilibrium molecular dynamics simulations.
منابع مشابه
Phase transitions in crystalline materials
We reviewed structural phase transitions in crystalline materials, especially recent simulations and experiments on the shock-induced transitions in iron. They both confirmed a phase transition wave in the picosecond to nanosecond time scale, inferred previously from wave profile analyses. The nonequilibrium molecular dynamics simulation suggests modification of pair potentials from temperature...
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عنوان ژورنال:
- Physical review letters
دوره 95 7 شماره
صفحات -
تاریخ انتشار 2005