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Two-dimensional (2D) magnetic materials promise unconventional properties and quantum phases as well as advances in ultra-compact spintronics. Miniaturization of 2D magnets often reaches a single monolayer but in general can go beyond this limit, as demonstrated by 2D magnetism of submonolayer Eu superstructures coupled with Si. The question is whether the submonolayer magnetism constitutes a general phenomenon. Herein, we demonstrate that regular Eu lattices form a class of 2D magnets displaying various structures, stoichiometries, and chemical bonding. We synthesized and studied a set of Eu superstructures on Ge(001). Their magnetic properties are consistent with the emergence of a magnetic order such as ferro- or ferrimagnetism. In particular, control over the magnetic transition temperature by weak magnetic fields indicates the 2D nature of the magnetism. Taken together, Eu/Ge and Eu/Si superstructures seed a nucleus of the research area addressing the emergence of magnetism in submonolayer chemical species.


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Submonolayer Eu superstructures—A class of 2D magnets

Show Author's information Dmitry V. AveryanovIvan S. SokolovAlexander N. TaldenkovOleg E. ParfenovAndrey M. TokmachevVyacheslav G. Storchak( )
National Research Center “Kurchatov Institute”, Kurchatov Sq. 1, Moscow 123182, Russia

Abstract

Two-dimensional (2D) magnetic materials promise unconventional properties and quantum phases as well as advances in ultra-compact spintronics. Miniaturization of 2D magnets often reaches a single monolayer but in general can go beyond this limit, as demonstrated by 2D magnetism of submonolayer Eu superstructures coupled with Si. The question is whether the submonolayer magnetism constitutes a general phenomenon. Herein, we demonstrate that regular Eu lattices form a class of 2D magnets displaying various structures, stoichiometries, and chemical bonding. We synthesized and studied a set of Eu superstructures on Ge(001). Their magnetic properties are consistent with the emergence of a magnetic order such as ferro- or ferrimagnetism. In particular, control over the magnetic transition temperature by weak magnetic fields indicates the 2D nature of the magnetism. Taken together, Eu/Ge and Eu/Si superstructures seed a nucleus of the research area addressing the emergence of magnetism in submonolayer chemical species.

Keywords: surface reconstruction, superstructure, submonolayer, germanium, two-dimensional (2D) magnetism

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Publication history
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Acknowledgements

Publication history

Received: 18 May 2022
Revised: 16 June 2022
Accepted: 23 June 2022
Published: 30 July 2022
Issue date: January 2023

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© Tsinghua University Press 2022

Acknowledgements

Acknowledgements

This work is supported by NRC “Kurchatov Institute”, the Ministry of Science and Higher Education of Russia (Agreement No. 075-15-2021-1351), and the Russian Science Foundation (grants No. 22-13-00004 (synthesis), 20-79-10028 (structural characterization), and 19-19-00009 (studies on magnetism)). The measurements have been carried out using equipment of the resource centre of electrophysical techniques at NRC “Kurchatov Institute”.

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