Electron spin relaxation of N@C60 in CS2
| Autor: | Morton, JJL, Tyryshkin, AM, Ardavan, A, Porfyrakis, K, Lyon, SA, Andrew, G, Briggs, D |
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| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: |
Arrhenius equation
Coherence time Condensed Matter - Materials Science Materials science Spins Condensed matter physics Relaxation (NMR) Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences General Physics and Astronomy 02 engineering and technology Zero field splitting 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences symbols.namesake symbols Physics::Atomic and Molecular Clusters Molecule Physical and Theoretical Chemistry Physics::Chemical Physics 0210 nano-technology Spin relaxation |
| Popis: | We examine the temperature dependence of the relaxation times of the molecules N@C60 and N@C70 (which comprise atomic nitrogen trapped within a carbon cage) in liquid CS2 solution. The results are inconsistent with the fluctuating zero field splitting (ZFS) mechanism, which is commonly invoked to explain electron spin relaxation for S > 1/2 spins in liquid solution, and is the mechanism postulated in the literature for these systems. Instead, we find a clear Arrhenius temperature dependence for N@C60, indicating the spin relaxation is driven primarily by an Orbach process. For the asymmetric N@C70 molecule, which has a permanent non-zero ZFS, we resolve an additional relaxation mechanism caused by the rapid reorientation of its ZFS. We also report the longest coherence time (T2) ever observed for a molecular electron spin, being 0.25 ms at 170K. 6 pages, 6 figures V2: Updated to published version |
| Databáze: | OpenAIRE |
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