Measurement of the Induced Magnetic Polarisation of Rotated-Domain Graphene Grown on Co Film with Polarised Neutron Reflectivity

Razan Omar M Aboljadayel; Christy John Kinane; Carlos Antonio Fernandes Vaz; David Michael Love; Marie-Blandine Martin; Andrea Cabrero-Vilatela; Philipp Braeuninger-Weimer; Adrian Ionescu; Andrew John Caruana; Timothy Randall Charlton; Justin Llandro; Pedro Manuel da Silva Monteiro; Crispin Henry William Barnes; Stephan Hofmann; Sean Langridge

doi:10.3390/nano13192620

Measurement of the Induced Magnetic Polarisation of Rotated-Domain Graphene Grown on Co Film with Polarised Neutron Reflectivity

Nanomaterials (Basel). 2023 Sep 22;13(19):2620. doi: 10.3390/nano13192620.

Authors

Razan Omar M Aboljadayel¹, Christy John Kinane², Carlos Antonio Fernandes Vaz³, David Michael Love¹, Marie-Blandine Martin⁴, Andrea Cabrero-Vilatela⁴, Philipp Braeuninger-Weimer⁴, Adrian Ionescu¹, Andrew John Caruana², Timothy Randall Charlton², Justin Llandro¹, Pedro Manuel da Silva Monteiro¹, Crispin Henry William Barnes¹, Stephan Hofmann⁴, Sean Langridge²

Affiliations

¹ Cavendish Laboratory, Physics Department, University of Cambridge, Cambridge CB3 0HE, UK.
² ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxon OX11 0QX, UK.
³ Swiss Light Source, Paul Scherrer Institut (PSI), 5232 Villigen, Switzerland.
⁴ Department of Engineering, University of Cambridge, Cambridge CB3 0FA, UK.

Abstract

In this paper, we determine the magnetic moment induced in graphene when grown on a cobalt film using polarised neutron reflectivity (PNR). A magnetic signal in the graphene was detected by X-ray magnetic circular dichroism (XMCD) spectra at the C K-edge. From the XMCD sum rules an estimated magnetic moment of 0.3 μ_B/C atom, while a more accurate estimation of 0.49 μ_B/C atom was obtained by carrying out a PNR measurement at 300 K. The results indicate that the higher magnetic moment in Co is counterbalanced by the larger lattice mismatch between the Co-C (1.6%) and the slightly longer bond length, inducing a magnetic moment in graphene that is similar to that reported in Ni/graphene heterostructures.

Keywords: PNR; XMCD; graphene; heterostructures; magnetism.

Grants and funding

This research received no external funding.