Symmetry forbidden morphologies and domain boundaries in nanoscale graphene islands
Parreiras, Sofia de Oliveira (Institut Català de Nanociència i Nanotecnologia)
Gastaldo, Michele (Institut Català de Nanociència i Nanotecnologia)
Moreno, Cesar (Institut Català de Nanociència i Nanotecnologia)
Martins, M. D. (Centro de Desenvolvimento da Tecnologia Nuclear (CDTN))
Garcia-Lekue, Aran (Basque Foundation for Science)
Ceballos, Gustavo (Institut Català de Nanociència i Nanotecnologia)
Paniago, R. (Universidade Federal de Minas Gerais. Departamento de Física)
Mugarza, Aitor (Institut Català de Nanociència i Nanotecnologia)

Date:	2017
Abstract:	The synthesis of graphene nanoislands with tailored quantum properties requires an atomic control of the morphology and crystal structure. As one reduces their size down to the nanometer scale, domain boundary and edge energetics, as well as nucleation and growth mechanisms impose different stability and kinetic landscape from that at the microscale. This offers the possibility to synthesize structures that are exclusive to the nanoscale, but also calls for fundamental growth studies in order to control them. By employing high-resolution scanning tunneling microscopy we elucidate the atomic stacking configurations, domain boundaries, and edge structure of graphene nanoislands grown on Ni(1 1 1) by CVD and post-annealed at different temperatures. We find a non-conventional multistep mechanism that separates the thermal regimes for growth, edge reconstruction, and final stacking configuration, leading to nanoisland morphologies that are incompatible with their stacking symmetry. Whole islands shift their stacking configuration during cooling down, and others present continuous transitions at the edges. A statistical analysis of the domain structures obtained at different annealing temperatures reveals how polycrystalline, ill-defined structures heal into shape-selected islands of a single predominant stacking. The high crystallinity and the control on morphology and edge structure makes these graphene nanoislands ideal for their application in optoelectronics and spintronics.
Grants:	Ministerio de Economía y Competitividad MAT2013-46593-C6-2-P Ministerio de Economía y Competitividad MAT2013-46593-C6-5-P Agencia Estatal de Investigación MAT2016-78293-C6-2-R Agencia Estatal de Investigación MAT2016-78293-C6-4-R Ministerio de Economía y Competitividad SEV-2013-0295 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-715 European Commission 610446 European Commission 600385
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Graphene nanostructures ; CVD ; Atomic stacking ; Domain boundaries
Published in:	2D materials, Vol. 4, Núm. 2 (May 2017) , art. 25104, ISSN 2053-1583

DOI: 10.1088/2053-1583/aa70fa

Postprint 17 p, 3.1 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles