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Your search keyword '"Güell, Aleix G."' showing total 28 results
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28 results on '"Güell, Aleix G."'

3. Nanomechanics of silicon surfaces with atomic force microscopy: An insight to the first stages of plastic deformation.

Author

Garcia-Manyes, Sergi, Güell, Aleix G., Gorostiza, Pau, and Sanz, Fausto

Subjects
*NANOTECHNOLOGY, *ATOMIC force microscopy, *SILICON, *NONMETALS, *SCANNING probe microscopy, *MICROSCOPY
Abstract

The use of stiff cantilevers with diamond tips allows us to perform nanoindentations on hard covalent materials such as silicon with atomic force microscopy. Thanks to the high sensitivity in the force measurements together with the high resolution upon imaging the surface, we can study nanomechanical properties. At this scale, the surface deforms, following a simple non-Hertzian spring model. The plastic onset can be assessed from a discontinuity in the force-distance curves. Hardness measurements with penetration depths as small as 1 nm yield H=∼25 GPa, thus showing a drastic increase with penetration depths below 5 nm. [ABSTRACT FROM AUTHOR]

Published
2005
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27. Mapping Nanoscale Electrochemistry of Individual Single-WalledCarbon Nanotubes.

Author

Güell, Aleix G., Meadows, Katherine E., Dudin, Petr V., Ebejer, Neil, Macpherson, Julie V., and Unwin, Patrick R.

Subjects
*NANOCHEMISTRY, *ELECTROCHEMISTRY, *SINGLE walled carbon nanotubes, *ELECTRODES, *MATHEMATICAL mappings, *HIGH resolution imaging
Abstract

Weintroduce a multiprobe platform for the investigation of single-walledcarbon nanotubes (SWNTs) that allows the electrochemical responseof an individual SWNT to be mapped at high spatial resolution andcorrelated directly with the intrinsic electronic and structural properties.With this approach, we develop a detailed picture of the factors controllingelectrochemistry at SWNTs and propose a definitive model that hasmajor implications for future architectures of SWNT electrode devices. [ABSTRACT FROM AUTHOR]

Published
2014
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28. Spatial and Temporal Control of the Diazonium Modification of sp² Carbon Surfaces.

Author

Kirkman, Paul M., Güell, Aleix G., Cuharuc, Anatolii S., and Unwin, Patrick R.

Subjects
*DIAZONIUM compounds, *CARBON, *GRAPHENE, *BAND gaps, *SCANNING electrochemical microscopy, *ATOMIC force microscopy, *SURFACE analysis, *RAMAN spectroscopy
Abstract

Interest in the controlled chemical functionalization of sp² carbon materials using diazonium compounds has been recently reignited, particularly as a means to generate a band gap in graphene. We demonstrate local diazonium modification of pristine sp² carbon surfaces, with high control, at the micrometer scale through the use of scanning electrochemical cell microscopy (SECCM). Electrochemically driven diazonium patterning is investigated at a range of driving forces, coupled with surface analysis using atomic force microscopy (AFM) and Raman spectroscopy. We highlight how the film density, level of sp²/sp³ rehybridization and the extent of multilayer formation can be controlled, paving the way for the use of localized electrochemistry as a route to controlled diazonium modification. [ABSTRACT FROM AUTHOR]

Published
2014
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