Capillary and van der Waals interactions on CaF crystals from amplitude modulation AFM force reconstruction profiles under ambient conditions
Calò, Annalisa (Institut Català de Nanociència i Nanotecnologia)
Vidal Robles, Oriol (Institut Català de Nanociència i Nanotecnologia)
Santos, Sergio (Universitat Politècnica de Catalunya. Departament de Disseny i Programació de Sistemes Electrònics)
Verdaguer Prats, Albert (Institut Català de Nanociència i Nanotecnologia)

Fecha:	2015
Resumen:	There has been much interest in the past two decades to produce experimental force profiles characteristic of the interaction between nanoscale objects or a nanoscale object and a plane. Arguably, the advent of the atomic force microscope AFM was instrumental in driving such efforts because, in principle, force profiles could be recovered directly. Nevertheless, it has taken years before techniques have developed enough as to recover the attractive part of the force with relatively low noise and without missing information on critical ranges, particularly under ambient conditions where capillary interactions are believed to dominate. Thus a systematic study of the different profiles that may arise in such situations is still lacking. Here we employ the surfaces of CaF, on which nanoscale water films form, to report on the range and force profiles that might originate by dynamic capillary interactions occurring between an AFM tip and nanoscale water patches. Three types of force profiles were observed under ambient conditions. One in which the force decay resembles the well-known inverse-square law typical of van der Waals interactions during the first 0. 5-1 nm of decay, a second one in which the force decays almost linearly, in relatively good agreement with capillary force predicted by the constant chemical potential approximation, and a third one in which the attractive force is almost constant, i. e. , forms a plateau, up to 3-4 nm above the surface when the formation of a capillary neck dominates the tip-sample interaction.
Ayudas:	Ministerio de Economía y Competitividad SEV-2013-0295 Ministerio de Economía y Competitividad MAT2012-38319-C02-01
Derechos:	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.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Amplitude modulation (AM) AFM ; Dynamic capillary interactions ; Dissipative nanoscale interactions ; CaF wetting ; Force reconstruction
Publicado en:	Beilstein journal of nanotechnology, Vol. 6 (2015) , p. 809-819, ISSN 2190-4286

DOI: 10.3762/bjnano.6.84
PMID: 25977852

11 p, 1.8 MB

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Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > Institut Català de Nanociència i Nanotecnologia (ICN2)
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