Unraveling the influence of lanthanide ions on intra- and inter-molecular electronic processes in Fe 10 Ln 10 nano-toruses

Journal article

We investigated the electronic properties of the molecular magnetic nanoto-ruses [Fe III10LnIII10(Me-tea)10(Me-teaH)10(NO3)10], examining the dependence on the lanthanide (Ln) of both the intra and intermolecular electronic channels. Using femtosecond absorption spectroscopy we show that the intramolecular electronic channels follow a three-step process, which involves vibrational cooling and crossing to shallow states, followed by recombination. A comparison with the energy gaps showed a relationship between trap efficiency and gaps, indicating that lanthanide ions create trap states to form excitons after photo-excitation. Using high-resistance transport measurements and scaling techniques, we investigated the intermolecular transport, demonstrating the dominant role of surface-limited transport channels and the presence of different types of charge traps. The intermolecular transport properties can be rationalized in terms of a hopping model, and a connection is provided to the far-IR spectroscopic properties. Comparison between intra and intermolecular processes highlights the role of the excited electronic states and the recombination processes, showing the influence of Kramers parity on the overall mobility.

Authors: Baniodeh, A; Liang, Y; Anson, C; Magnani, N; Powell, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Advanced Functional Materials
• Volume: 24
• Issue: 40
• Pages: 6280–6290
• Publication date: 2014-10-22
• Acceptance date: 2014-04-17
• DOI: 10.1002/adfm.201400336
• ISSN: 1616-3028 and 1616-301X
• Keywords: SBTMR