Fe intercalation under graphene and hexagonal boron nitride in-plane heterostructure on Pt(111)

We have investigated the process of thermally-stimulated Fe intercalation under a single layer h-BNG heterostructure prepared on Pt(111) and the influence of coadsorbed oxygen.

I. Píš, et al.Carbon 134, 274-282 (2018) 
DOI10.1016/j.carbon.2018.03.086

Metal nanostructures confined between sp2 hybridized 2D materials and solid supports are attracting attention for their potential application in new nanotechnologies. Model studies under well-defined conditions are valuable for understanding the fundamental aspects of the phenomena under 2D covers. In this work we investigate the intercalation of iron atoms through a single layer of mixed graphene and hexagonal boron nitride on Pt(111) using a combination of spectroscopic (x-ray photoemission and soft x-ray absorption spectroscopy at the BACH beamline) and microscopic techniques (XPEEM, XAS-PEEM and LEEM at the Nanospectroscopy beamline).  Compared with pure single Gr layer, h-BNG layer requires higher temperature to complete the iron diffusion. Upon annealing, iron migrates and agglomerates preferentially between Pt(111) and Gr domains and only partially between h-BN and Pt(111)Oxygen coadsorbed with iron during the deposition promotes the intercalation: when oxygen is coadsorbed with iron, the intercalation rate is higher. A temperature of 700 K is found sufficient to intercalate 1 ML Fe deposited in low-pressure oxygen atmosphere. The oxygen bound to iron is released upon annealing, reacts with boron in h-BNG and forms B2O3 and C-B-O functional groups.
Our results indicate that thin Fe layers and compounds of
particular configuration can be grown and stabilized under h-BNG 2D cover. This finding opens up the opportunity to study their electronic, magnetic, as well as catalytic properties.  This work suggest for example the possibility of confining ferromagnetic layers under heterostructures of graphene and hexagonal boron nitride with potential technological implications in the fields of spintronics, magnetic data storage or chemistry under 2D covers. Fe-based nanocatalysts covered with sp2 hybridized shell may exhibit also intriguing activity or selectivity in many chemical reactions.

This work was supported by the Italian MIUR through the national grant Futuro in ricerca 2012 RBFR128BEC ‘‘Beyond graphene: tailored C-layers for novel catalytic materials and green chemistry’’

 

and “Progetto Premiale 2012”–Project ABNANOTECH. Federico Salvador, Davide Benedetti, Aleksander De Luisa and Paolo Bertoch are acknowledged for technical support.

Fe intercalation under graphene and hexagonal boron nitride in-plane heterostructure on Pt(111)
Igor Píš; Silvia Nappini; Federica Bondino, Onur Tevfik Mentes; Alessandro Sala; Andrea Locatelli; Elena Magnano

Carbon 134, 274-282 (2018) 
DOI10.1016/j.carbon.2018.03.086.

Accepted manuscript is available on ArXiv:


 

 

Last Updated on Thursday, 14 January 2021 12:11