Dr. Angel Rubio Profile

Dr. Angel Rubio

Professor at Univ del País Vasco

SPIE Involvement:

Author

Proceedings Article | 29 April 2003 Paper

Vibrational properties of boron nitride nanotubes: Effects of finite length and bundling

Ludger Wirtz, Angel Rubio

Proceedings Volume 5118, (2003) https://doi.org/10.1117/12.499369

KEYWORDS: Phonons, Raman spectroscopy, Chemical species, Infrared spectroscopy, Carbon, Spectroscopy, Boron, Infrared radiation, Carbon nanotubes, Raman scattering

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Proceedings Article | 29 April 2003 Paper

Molecular clusters of hydrogen, deuterium, and tritium: especially cationic species H+3 (H2)m: m=2, 5 and 14

I. Howard, Frederik Leys, N. March, C. Van Alsenoy, Julio Alonso, Angel Rubio

Proceedings Volume 5118, (2003) https://doi.org/10.1117/12.502152

KEYWORDS: Ions, Hydrogen, Molecules, Physics, Chemical species, Crystals, Ionization, Chemistry, Nanotechnology, Electroluminescence

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Proceedings Article | 29 April 2003 Paper

Deformations and thermal stability of carbon nanotube ropes

Maria Lopez, Angel Rubio, Julio Alonso

Proceedings Volume 5118, (2003) https://doi.org/10.1117/12.502002

KEYWORDS: Picosecond phenomena, Carbon nanotubes, Crystals, Chemical species, Polymerization, Laser crystals, Carbon, Graphene, Annealing, Computer simulations

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As it is well known, carbon nanotubes may be one fold (Single Wall Carbon Nanotubes, SWCNT) or contain several cylinders nested one inside another (Multi Wall Carbon Nanotubes, MWCNT). SWCNT's, in many cases, self-organize into crystalline bundles (set of a few to a few hundred aligned tubes arranged in a two-dimensional triangular lattice in the plane perpendicular to their common axes). A thorough understanding of carbon nanotubes (CNT's) includes the detailed and comprehensive characterization of their possible deformations due to interactions with a substrate or with other tubes, and their stability under thermal treatment or chemical agents. In this communication we concentrate on i) the structural characteristics and ii) the structural transformations under thermal treatment of bundles of SWCNT's. i) Deformations of the tubes away from their ideal circular cross sections may have non trivial effects in their properties such as conductivity or phonon spectrum. We have being able to synthesize novel crystalline bundles of 'polygonized' SWCNT's. Our finding opens up the question of what is the equilibrium configuration of a lattice of aligned tubes and the possibility of the existence of several metastable structures which could be obtained depending on the growth conditions. To shed some light on this problem we have performed extensive molecular dynamics simulations of lattices of monodisperse armchair and zigzag SWCNT's as a function of tube diameter. We find several metastable structures of the lattice characterized by different tube cross sections, hexagonal, rounded-hexagonal and circular, and increasing cell volume. The competition between different tube shapes is analyzed and compared to experiments. ii) On the other hand, CNT's are metastable; (the most stable form of carbon is graphite). Due to their metastable character CNT's may transform into more stable structures under the appropriate annealing conditions. We have found that bundles of SWCNT's coalesce forming MWCNT's, containing from two to six nested tubes, under thermal treatment at high temperatures. This structural transformation is confirmed by extensive Molecular Dynamics (MD) simulations. The simulations suggest a 'patching--and--tearing' mechanism for the SW-- to MWCNT's transformation underlying the 'concerted' coalescence of the tubes that begins with their polymerization. Tubes of different sizes and chiralities are considered.

Proceedings Article | 29 April 2003 Paper

Interaction of molecular and atomic hydrogen with single-wall carbon nanotubes

Julio Alonso, Juan Arellano, Luis Molina, Angel Rubio, Maria Lopez

Proceedings Volume 5118, (2003) https://doi.org/10.1117/12.500133

KEYWORDS: Molecules, Hydrogen, Chemical species, Absorption, Molecular interactions, Carbon, Graphene, Carbon nanotubes, Chemisorption, Single walled carbon nanotubes

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SPIE Conference Volume | 29 April 2003

Nanotechnology

Conference Committee Involvement (2)

Nanotechnology II

9 May 2005 | Sevilla, Spain

Nanotechnology

19 May 2003 | Maspalomas, Gran Canaria, Canary Islands, Spain

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