How to measure the magnetism of a graphene nanostructure

2023-10-25 11:02:19

A team of scientists led by David SerrateCSIC researcher at the Institute of Nanoscience and Materials of Aragon (INMA), has managed to measure for the first time the magnetic behavior of a nanostructure of graphene.

The work is published in the magazine Nature Communicationswhere the authors not only reveal the magnetic state of narrow graphene ribbons (about 2 nanometers), but also present the method they have developed to magnetically characterize any planar nanographene.

The magnetic behavior of a graphene nanostructure has been measured for the first time and the method to do so is presented

Besides of INMA (a joint institute of the CSIC and the University of Zaragoza), other Spanish centers have participated in this research: DIPC (Donostia International Physics Center), CINN (Nanomaterials & Nanotechnology Research center, CSIC-University of Ovideo), CFM (Center for Materials Physics, CSIC-University of the Basque Country) and CIQUS (Singular Research Center in Biological Chemistry and Molecular Materials , at the University of Santiago de Compostela). The experimental development was carried out in the Advanced Microscopy Laboratory (LMA) of the University of Zaragoza.

To carry out the study, we started from a specifically designed organic precursor and synthesized the ribbons directly on a magnetic surface, obtaining atomically precise edges consisting of an alternating sequence of segments of grapheno and zig-zag.

This geometry allows the graphene electron cloud to be strongly confined around its edge, which causes an instability that is responsible for the intrinsic magnetism of the graphene nanostructure, a notable fact considering that the tape is made up solely of non-magnetic carbon and hydrogen atoms.

Spin-polarized STM technique

The detection method is the technique STM (scanning tunneling microscopy) spin polarizeda type of microscopy that takes images of the electron current flowing between the sample and an atomically sharp needle capable of counting how many electrons travel with one magnetization or another.

An atomically sharp needle is capable of counting how many electrons travel with one or another magnetization

Graphene nanostructures of this and other types are of great interest for the engineering of electronic states, since they have tailored magnetic and quantum properties.

The so-called synthesis techniques bottom-up have managed to produce atomically perfect structures with controlled size, shape and edge topology. Thanks to their versatility, low production cost and dimensions within the quantum scale, they are considered an excellent alternative to silicon-based electronic devices.

Research in this field is aimed at preserving the quantum properties and improve the quantum coherence of this type of tapes. “Within a few years we will be able to offer proof of concept of an organic, self-assembled quantum bit… or so I hope!” says Serrate.

Fuente: INMA

Rights: Creative Commons.