大型放射光施設 SPring-8

日時：　2006年12月19日 13:30～14:30

場所：　SPring-8普及棟中講堂

講演者：　Paul Fons （独立行政法人 産業技術総合研究所）

講演タイトル：　相変化の瞬間を捉える：時分割XAFSによる相変化記録合金 Ge₂Sb₂Te₅ の転移過程の観察
（Fons氏は日本語も堪能ですので、講演は日本語、英語どちらでも可能です。聴講者に外国人の方が多ければ、英語で行うかもしれません。）

要旨：　Phase-change alloys constitute the basis for a widening collection of storage technologies both optical and electrical. These uses of phase-change alloys are characterized by reversible switching between amorphous and crystalline phases either by laser irradiation or by an electric current; the resulting changes in material properties can be used for non-volitile data storage. Switching typically occurs on the nanosecond time scale. Considering the conflicting requirements for high-speed switching, yet long term data storage integrity, a deeper understanding of the switching processes in these materials is essential for insightful application development. We have used synchrotron-based time-resolved x-ray absorption fine structure spectroscopy (XAFS), a technique equally suitable for amorphous and crystalline phases to elaborate details in structural changes in the phase-change process on a sub-nanosecond time scale using optical pump/x-ray probe techniques. In this work, we present initial results of sub-nanosecond laser excitation of the laser-reamorphized state of Ge₂Sb₂Te₅. The technique is general and can be applied to a wide variety of nanoscale structures. Preliminary results taken at the Advanced Photon Source as well as recent experiments taken at SPring-8 will be discussed.

担当者：　鈴木基寛　(phs 3871)