Shantanu Mishra^1*, Xuelin Yao², Qiang Chen², Kristjan Eimre¹, Oliver Gröning¹, Ricardo Ortiz^3,4, Marco Di Giovannantonio¹, Juan Carlos Sancho-García⁴, Joaquín Fernández-Rossier⁵, Carlo A. Pignedoli¹, Klaus Müllen², Pascal Ruffieux¹, Akimitsu Narita^2,6, Roman Fasel^1,7*

1 Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland

2 Department of Synthetic Chemistry, Max Planck Institute for Polymer Research, 55021 Mainz, Germany

3 Department of Applied Physics, University of Alicante, Sant Vicent del Raspeig, Spain

4 Department of Chemical Physics, University of Alicante, Sant Vicent del Raspeig, Spain

5 QuantaLab, International Iberian Nanotechnology Laboratory, Braga, Portugal

6 Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan

7 Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland

* Corresponding authors emails: shantanu.mishra@empa.ch, roman.fasel@empa.ch

DOI10.24435/materialscloud:vv-y6 [version v1]

Publication date: Oct 28, 2021

How to cite this record

Shantanu Mishra, Xuelin Yao, Qiang Chen, Kristjan Eimre, Oliver Gröning, Ricardo Ortiz, Marco Di Giovannantonio, Juan Carlos Sancho-García, Joaquín Fernández-Rossier, Carlo A. Pignedoli, Klaus Müllen, Pascal Ruffieux, Akimitsu Narita, Roman Fasel, Large magnetic exchange coupling in rhombus-shaped nanographenes with zigzag periphery, Materials Cloud Archive 2021.178 (2021), doi: 10.24435/materialscloud:vv-y6.

Description

In this record we provide data to support our recent findings for the magnetic properties of rhombus-shaped nanographenes. Nanographenes with zigzag edges are predicted to manifest non-trivial π-magnetism resulting from the interplay of concurrent electronic effects, such as hybridization of localized frontier states and Coulomb repulsion between valence electrons. This provides a chemically tunable platform to explore quantum magnetism at the nanoscale and opens avenues towards organic spintronics. The magnetic stability in nanographenes is thus far greatly limited by the weak magnetic exchange coupling, which remains below the room-temperature thermal energy. In our work, we report the synthesis of large rhombus-shaped nanographenes with zigzag peripheries on gold and copper surfaces. Single-molecule scanning probe measurements show an emergent magnetic spin singlet ground state with increasing nanographene size. The magnetic exchange coupling in the largest nanographene (C70H22, containing five benzenoid rings along each edge), determined by inelastic electron tunnelling spectroscopy, exceeds 100 meV or 1,160 K, which outclasses most inorganic nanomaterials and survives on a metal electrode.

Materials Cloud sections using this data

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File name	Size	Description
ReadMe.yaml MD5md5:8481acd7e3a43a3b6e0282abd562aa28	49.0 KiB	ReadMe file in yaml format detailing the content of the record
data.tgz MD5md5:c7d9105229e492222fd658aa2958a4fb	48.8 MiB	Compressed tar file containing the files of the record
rhombenes_gas.aiida MD5md5:79b7a45aedad2bbb7a49300e750b6be1 Open this AiiDA archive on renkulab.io (https://renkulab.io/)	349.6 KiB	Archive containing AiiDA nodes to reproduce gas phase DFT calculations

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External references

Keywords

nanographenes magnetic carbon ab initio MARVEL/DD3 SNSF CSCS Horizon 2020 Graphene flagship