| 研究実績の概要 |
The structural order of metallic glasses beyond SRO (short-range order) has been intensely discussed before. Although X-ray and neutron diffraction profiles provide strong indication of the existence of MRO (medium-range order) in metallic glasses, the average structure information derived from broad diffraction peaks cannot provide consistent structure information on true atomic arrangements in real space. Classical MD and ab initio MD simulations have been proved to be effective in determining SRO in metallic glasses, however, the MD simulation takes too long time to reveal formation of MRO.
We have successfully developed scanning ABED (angstrom beam electron diffraction), which is probably the only technique that is capable of experimentally elucidating the atomic arrangements in metallic glasses beyond SRO by providing non-averaged two dimensional diffraction patterns with a high spatial resolution of 0.2 nm. This scanning ABED unravels MRO of metallic glasses and constructed plausible MRO models based on the experimental data.
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