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arXiv 0802.0811cond-mat.mtrl-sci
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C80富勒烯笼内的可切换ErSc2N转子:EPR和光致发光激发研究

Switchable ErSc2N rotor within a C80 fullerene cage: An EPR and photoluminescence excitation study

John J. L. Morton, Archana Tiwari, Geraldine Dantelle, Kyriakos Porfyrakis, Arzhang Ardavan, G. Andrew D. Briggs

摘要:

表现出自旋和轨道自由度的系统,其中Er 3+是一个,可以提供通过光学激发操纵和测量自旋状态的机制。出于观察光致发光和电子顺磁共振从位于富勒烯分子内的同一物种的可能性,我们开始了EPR研究Er 3+在ErSc2N@C80。在EPR中观察到C80富勒烯内ErSc 2N转子的两个取向,与早期使用光致发光激发(PLE)光谱的研究一致。对于某些晶场取向,电子自旋弛豫是通过4I_15/2多重态的第一激发电子态由Orbach过程驱动的。我们观察到的两个ErSc 2N配置的相对人口的变化后,应用532 nm的照明,从而能够切换多数笼对称性。EPR和PLE都能观察到的这种光异构化是亚稳态的,在20 K下持续数小时。

英文摘要:

Systems exhibiting both spin and orbital degrees of freedom, of which Er3+ is one, can offer mechanisms for manipulating and measuring spin states via optical excitations. Motivated by the possibility of observing photoluminescence and electron paramagnetic resonance from the same species located within a fullerene molecule, we initiated an EPR study of Er3+ in ErSc2N@C80. Two orientations of the ErSc2N rotor within the C80 fullerene are observed in EPR, consistent with earlier studies using photoluminescence excitation (PLE) spectroscopy. For some crystal field orientations, electron spin relaxation is driven by an Orbach process via the first excited electronic state of the 4I_15/2 multiplet. We observe a change in the relative populations of the two ErSc2N configurations upon the application of 532 nm illuminations, and are thus able to switch the majority cage symmetry. This photoisomerisation, observable by both EPR and PLE, is metastable, lasting many hours at 20 K.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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