Direct observation of large strain through van der Waals gaps on epitaxial Bi2Te3/graphite: pseudomorphic relaxation and the role of Bi2 layers on the BixTey topological insulator series

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dc.creatorGilberto Rodrigues da Silva Junior
dc.creatorLucas Atila Bernardes Marçal
dc.creatorGuilherme Almeida Silva Ribeiro
dc.creatorPaulo Henrique de Oliveira Rappl
dc.creatorEduardo Abramof
dc.creatorPaulo Victor Sciammarella Maia
dc.creatorLuciano de Moura Guimarães
dc.creatorCarlos Alberto Pérez
dc.creatorÂngelo Malachias de Souza
dc.date.accessioned2023-03-21T14:59:05Z
dc.date.accessioned2025-09-09T01:15:18Z
dc.date.available2023-03-21T14:59:05Z
dc.date.issued2020-02-12
dc.description.sponsorshipCNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico
dc.description.sponsorshipFAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais
dc.description.sponsorshipCAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
dc.description.sponsorshipFAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo
dc.identifier.doihttps://doi.org/10.1103/PhysRevMaterials.4.023602
dc.identifier.issn2475-9953
dc.identifier.urihttps://hdl.handle.net/1843/51084
dc.languageeng
dc.publisherUniversidade Federal de Minas Gerais
dc.relation.ispartofPhysical Review Materials
dc.rightsAcesso Restrito
dc.subjectDifração
dc.subjectRaios X
dc.subjectFilmes ultrafinos
dc.subjectMatéria condensada
dc.subject.otherEpitaxial strain
dc.subject.otherUltrathin films
dc.subject.otherX-ray diffraction
dc.subject.otherCondensed matter
dc.titleDirect observation of large strain through van der Waals gaps on epitaxial Bi2Te3/graphite: pseudomorphic relaxation and the role of Bi2 layers on the BixTey topological insulator series
dc.typeArtigo de periódico
local.citation.epage023602-10
local.citation.issue2
local.citation.spage023602-1
local.citation.volume4
local.description.resumoLayered materials can usually grow without strain on top of distinct substrates if the only interaction between them is due to van der Waals forces. In such a scenario it would be expected that the heterointerface made up of weak bounds would not affect the overlayed material significantly for several large lattice-mismatched systems. Here we have studied the first stages of the heteroepitaxial growth of layered bismuth telluride topological insulator on top of highly oriented pyrolitic graphite (HOPG) by molecular beam epitaxy. Samples were investigated by atomic force microscopy (AFM), synchrotron x-ray diffraction (XRD), and micro-Raman spectroscopy. AFM images show hexagonal/triangular flat islands with exposed HOPG areas for the low coverage regime, and the lattice parameter of these Bi2Te3 structures were measured by XRD. The existence of pseudomorphic strain at the initial Bi2Te3 layers was retrieved by both XRD and Raman spectroscopy. We have found evidence that Bi2Te3 layers near the interface are subject to an in-plane compressive strain, leading to a pseudomorphic out-of-plane lattice expansion. Furthermore, the presence of Bi2Te3 islands locally distorts the topmost layer of HOPG, resulting in tensile strain which was measured by Raman spectroscopy. The observed relaxation of 0.1–0.2% for each van der Waals gap is used to calculate elastic constants of Bi2 bilayers, which are crucial building blocks for the formation of other BixTey topological insulator compounds. Finally, the impact of such a strain in Bi2Te3 electronic structure was investigated by density functional theory calculations. The results show that the band structure of this strained material remains unchanged at the center of the Brillouin zone, confirming the robustness of surface states, but it is consistently affected at the M and K zone edges.
local.identifier.orcidhttps://orcid.org/0000-0001-6180-5302
local.identifier.orcidhttps://orcid.org/0000-0003-4956-5144
local.identifier.orcidhttps://orcid.org/0000-0002-4050-9560
local.identifier.orcidhttps://orcid.org/0000-0001-7560-7470
local.identifier.orcidhttps://orcid.org/0000-0002-1767-1375
local.identifier.orcidhttps://orcid.org/0000-0001-9656-2996
local.identifier.orcidhttps://orcid.org/0000-0003-4284-3148
local.identifier.orcidhttps://orcid.org/0000-0002-8703-4283
local.publisher.countryBrasil
local.publisher.departmentICX - DEPARTAMENTO DE FÍSICA
local.publisher.initialsUFMG
local.url.externahttps://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.4.023602

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