Large Magnetoresistance in Single-Radical Molecular Junctions.
| Autor: | Hayakawa R; International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan., Karimi MA, Wolf J, Huhn T, Zöllner MS; Institute for Inorganic and Applied Chemistry, University of Hamburg , Martin-Luther-King-Platz 6, 20146 Hamburg, Germany., Herrmann C; Institute for Inorganic and Applied Chemistry, University of Hamburg , Martin-Luther-King-Platz 6, 20146 Hamburg, Germany., Scheer E |
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| Jazyk: | angličtina |
| Zdroj: | Nano letters [Nano Lett] 2016 Aug 10; Vol. 16 (8), pp. 4960-7. Date of Electronic Publication: 2016 Aug 01. |
| DOI: | 10.1021/acs.nanolett.6b01595 |
| Abstrakt: | Organic radicals are promising building blocks for molecular spintronics. Little is known about the role of unpaired electrons for electron transport at the single-molecule level. Here, we examine the impact of magnetic fields on electron transport in single oligo(p-phenyleneethynylene) (OPE)-based radical molecular junctions, which are formed with a mechanically controllable break-junction technique at a low temperature of 4.2 K. Surprisingly huge positive magnetoresistances (MRs) of 16 to 287% are visible for a magnetic field of 4 T, and the values are at least 1 order of magnitude larger than those of the analogous pristine OPE (2-4%). Rigorous analysis of the MR and of current-voltage and inelastic electron-tunneling spectroscopy measurements reveal an effective reduction of the electronic coupling between the current-carrying molecular orbital and the electrodes with increasing magnetic field. We suggest that the large MR for the single-radical molecular junctions might be ascribed to a loss of phase coherence of the charge carriers induced by the magnetic field. Although further investigations are required to reveal the mechanism underlying the strong MR, our findings provide a potential approach for tuning charge transport in metal-molecule junctions with organic radicals. |
| Databáze: | MEDLINE |
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