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Papers by J. Gómez-herrero

Materials Today Chemistry

Measurements of room temperature electronic transport in pulled metallic nanowires are presented,... more Measurements of room temperature electronic transport in pulled metallic nanowires are presented, demonstrating that the conductance characteristics depend on the length, lateral dimensions, state and degree of disorder, and elongation mechanism of the wire. Conductance during elongation of short wires, exhibits periodic quantization steps with characteristic dips, correlating with the order-disorder states of layers of atoms in the wire, predicted via molecular dynamics simulations. The resistance of long wires, as long as 1 400 Å, exhibits localization characteristics with ln R(l) ~ l

Electronic transport in carbon nanotubes has been a field of intensive research in the last years... more Electronic transport in carbon nanotubes has been a field of intensive research in the last years. Up to date most of the works have been focused on the defect-free nanotubes, but defects are known to modify the electronic properties of carbon nanotubes. In this work we report direct evidences of the influence of artificially induced defects, on the electronic quantum transport in single walled carbon nanotubes. Defects are induced in single walled carbon nanotubes by Ar + ionic bombardment. Consecutive ion irradiation doses are applied to nanotubes producing a uniform density of defects. After each dose the electrical characteristics of the same carbon nanotube are measured by using a conductive atomic force microscopy. Using this method we are able to measure the resistance vs. Length characteristic of the nanotube [1] after each known dose of Ar + ions. The results are fitted to R(L) = R C+R 0/2·exp(L / L 0) indicating electronic transport in the Anderson localization regime. The...

M. Jaafar, D. Martínez, R. Pérez, J. Gómez – Herrero, O. IglesiasFreire, L. E. Serrano, R. Ibarra... more M. Jaafar, D. Martínez, R. Pérez, J. Gómez – Herrero, O. IglesiasFreire, L. E. Serrano, R. Ibarra, J. Ma de Teresa and A. Asenjo 1 Dpto. Física de la Materia Condensada, Universidad Autónoma de Madrid, Spain 2 Dpto. Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Spain 3 Instituto de Ciencia de Materiales de Madrid, CSIC, Spain 4 Instituto de Ciencia de Materiales de Aragón, CSIC, Zaragoza, Spain 5 Instituto de Nanociencia de Aragón, Zaragoza, Spain

ACS nano, Jan 18, 2018

The future of 2D flexible electronics relies on the preparation of conducting ultrathin films of ... more The future of 2D flexible electronics relies on the preparation of conducting ultrathin films of materials with mechanical robustness and flexibility in a simple but controlled manner. In this respect, metal-organic compounds present advantages over inorganic laminar crystals owing to their structural, chemical, and functional diversity. While most metal-organic compounds are usually prepared in bulk, recent work has shown that some of them are processable down to low dimensional forms. Here we report the one-pot preparation, carried out at the water-air interface, of ultrathin (down to 4 nm) films of the metal-organic compound [CuI(TAA)] (TAA= thioacetamide). The films are shown to be homogeneous over mm areas, smooth, highly transparent, mechanically robust, and good electrical conductors with memristive behavior at low frequencies. This combination of properties, as well as the industrial availability of the two building blocks required for the preparation, demonstrates their wid...

Physical Review B, 2000

Tip-sample interaction in intermittent contact scanning force microscopy, also called tapping mod... more Tip-sample interaction in intermittent contact scanning force microscopy, also called tapping mode, is experimentally studied to determine under which conditions tip-sample contact is established. Force vs distance curves are made while the cantilever is oscillating at its resonance frequency. Cantilevers with different force constants driven at different oscillation amplitudes have been used. In addition, samples with different hardness, such as

Proceedings of the National Academy of Sciences, 2009

We study the physical origins of phase contrast in dynamic atomic force microscopy (dAFM) in liqu... more We study the physical origins of phase contrast in dynamic atomic force microscopy (dAFM) in liquids where low-stiffness microcantilever probes are often used for nanoscale imaging of soft biological samples with gentle forces. Under these conditions, we show that the phase contrast derives primarily from a unique energy flow channel that opens up in liquids due to the momentary excitation of higher eigenmodes. Contrary to the common assumption, phase-contrast images in liquids using soft microcantilevers are often maps of short-range conservative interactions, such as local elastic response, rather than tip-sample dissipation. The theory is used to demonstrate variations in local elasticity of purple membrane and bacteriophage ϕ29 virions in buffer solutions using the phase-contrast images.

Physical Review Letters, 2011

Nanotechnology, 2007

Ferritin nanoparticles have been deposited immobilized onto a properly modified gold surface by s... more Ferritin nanoparticles have been deposited immobilized onto a properly modified gold surface by specific covalent bonding through lysine rests at the ferritin external surface. Atomic force microscopy (AFM) images confirmed the existence of a single ferritin monolayer. This is an easy and flexible route to form stable ferritin networks, which are covalently fixed to a gold substrate.

Nanotechnology, 2002

... This evidence for conductivity within the nanotubes has been confirmed by taking images with ... more ... This evidence for conductivity within the nanotubes has been confirmed by taking images with the Kelvin probe technique as well as lift mode. ... Phys. Lett. 72 3461 de Pablo PJ, Colchero J, Luna M, Gómez-Herrero J and Baró AM 2000 Phys. Rev. ...