研究・研究者
研究会・セミナー
| 演 題 | 「What can we learn about Spin Systems from EPR and ENDOR at High Frequency?」 |
|---|---|
| 日 時 | 2009年11月13日(金) 16:30 |
| 講演者 | Johan (Hans) van Tol 博士 associate scholar scientist at the National High Magnetic Field Laboratory in Tallahassee, FL. |
| 場 所 | 研究棟201セミナー室 |
| 概 要 | Electron Paramagnetic Resonance has greatly evolved since the days of impurity centers in minerals. High frequencies have enabled increased resolution, and made possible the study of systems with large zero-field splittings and/or large exchange interactions, while multi-frequency EPR has contributed considerably to the study of dynamics of bio-molecules, in particular spin-labeled proteins. Here we will focus on the implementation of CW and especially Pulsed EPR at frequencies in the 100-400 GHz range, and the possibilities created by high-frequency EPR in the study of a variety of spin systems. E.g. the high resolution enables site- and orientation selective Electron Nuclear Double Resonance. Pulsed techniques furthermore enable the direct measurement of the relaxation parameters and the homogeneous linewidth. The direct single-phonon spin-lattice relaxation (SLR) can be considerably enhanced at high frequencies, and will in general be the dominant relaxation mechanism at low temperatures. A study of the SLR as a function of the frequency thus in principle allows the mapping of the phonon density of states. Secondly, the contribution of the electron-electron dipolar interactions to the spin-spin relaxation can be quenched at low temperatures, allowing the study of quite concentrated spin systems by pulsed EPR. First results of Pulsed EPR in single molecule magnets will be presented. |
| その他 | 強磁場EPRを用いて分子磁性体，生体関連物質等の研究をされている アメリカ国立強磁場研究所National High Magnetic Field Lab（タラハシ）の Johan (Hans) van Tol 博士に一般向けのセミナーをお願いしました． ご参加頂ければ幸いです． |
| お問合せ先 | 中村敏和（物質分子科学研究領域） |
