Unlocking higher harmonics in atomic force microscopy with gentle interactions
Santos, Sergio (Universitat Politècnica de Catalunya. Departament de Disseny i Programació de Sistemes Electrònics)
Barcons, Victor (Universitat Politècnica de Catalunya. Departament de Disseny i Programació de Sistemes Electrònics)
Font, Josep (Universitat Politècnica de Catalunya. Departament de Disseny i Programació de Sistemes Electrònics)
Verdaguer Prats, Albert (Institut Català de Nanociència i Nanotecnologia)

Date:	2014
Abstract:	In dynamic atomic force microscopy, nanoscale properties are encoded in the higher harmonics. Nevertheless, when gentle interactions and minimal invasiveness are required, these harmonics are typically undetectable. Here, we propose to externally drive an arbitrary number of exact higher harmonics above the noise level. In this way, multiple contrast channels that are sensitive to compositional variations are made accessible. Numerical integration of the equation of motion shows that the external introduction of exact harmonic frequencies does not compromise the fundamental frequency. Thermal fluctuations are also considered within the detection bandwidth of interest and discussed in terms of higher-harmonic phase contrast in the presence and absence of an external excitation of higher harmonics. Higher harmonic phase shifts further provide the means to directly decouple the true topography from that induced by compositional heterogeneity.
Grants:	Ministerio de Economía y Competitividad MAT2012-38319
Note:	The license is subject to the Beilstein Journal of Nanotechnology terms and conditions: http://www.beilstein-journals.org/bjnano
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Atomic force microscopy ; Chemistry ; Composition ; Heterogeneity ; Higher harmonics ; Phase
Published in:	Beilstein journal of nanotechnology, Vol. 5 (2014) , p. 268-277, ISSN 2190-4286

DOI: 10.3762/bjnano.5.29
PMID: 24778948

10 p, 2.3 MB

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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