Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas

Barcelona, Spain

Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas

Barcelona, Spain
SEARCH FILTERS
Time filter
Source Type

Malowney J.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Malowney J.,Institute Of Microelectronica Of Barcelona Consejo Superior Of Investigaciones Cientificas | Mestres N.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Borrise X.,Institute Of Microelectronica Of Barcelona Consejo Superior Of Investigaciones Cientificas | And 9 more authors.
Microelectronic Engineering | Year: 2013

Ordered arrays of crystalline complex oxides nanostructures are synthesized onto single crystal insulating substrates using a polyvinyl alcohol based electron beam resist precursor. The irradiated zones are insoluble in water (negative-tone resist) due to the electron induced cross linking. The high temperature treatment of the developed precursor samples leads to the formation of ordered arrays of nanodots for low irradiation doses and to the growth of epitaxially oriented nanowires for high irradiation dosages. A local characterization of the generated pattern is performed by atomic force microscopy and high resolution TEM. © 2013 Elsevier B.V. All rights reserved.


Calleja A.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Granados X.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Ricart S.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Oro J.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | And 9 more authors.
CrystEngComm | Year: 2011

BaZrO3 nanofibers were electrospun from a 0.25 M metal cation solution containing barium acetate and zirconium 2,4-pentadionate dissolved in glacial acetic acid. Polyvinylpyrrolidone was added to increase the solution viscosity and allow formation of hollow fibers during electrospinning. Microstructural evolution during thermal annealing at temperatures between 600 °C and 1400 °C was studied revealing crystal growth evolution. Strong grain coarsening is observed above 1200 °C, leading to linear and branched nanoparticle chains originating from the finer initial hollow nanofibers. Faceting of the nanoparticles occurs in the low-energy surfaces. On the other hand, grain boundaries are planar and follow the same facet planes as the nanoparticles. High resolution transmission electron microscopy reveals no general epitaxial relationship at the interface with the exception of a minor amount of low angle grain boundaries. © 2011 The Royal Society of Chemistry.


Gelabert-Serra M.J.,Polytechnic University of Catalonia | Sumper A.,Polytechnic University of Catalonia | Sumper A.,University of Barcelona | Granados X.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | And 3 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2011

The recent development, achieved on SC devices for grid applications, requires the support of design tools in order to establish the impact of these new devices on the operation of the electrical system. Classically, standard simulation programs are used in grid design and maintenance by the utilities; but these new devices require user written models, compatible with the grid simulators. In this paper, a user written model for the integration of superconducting cables in the grid, with the capacity to simulate dynamic behavior, is presented. Results of the simulations are presented which refer to the overall grid performance. © 2010 IEEE.


Punzi A.,University of Bari | Maiorano E.,University of Bari | Nicoletta F.,University of Catania | Blasi D.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | And 11 more authors.
European Journal of Organic Chemistry | Year: 2016

1,2,3-Triazole rings bearing hydrophobic aliphatic or hydrophilic oligoether chains were easily introduced at the two ends of the conjugated skeleton of bisthiophene-diketopyrrolopyrrole (TDPP) derivatives by simple click cycloaddition reactions. The combination of side chains with different structures and polarities on the triazole rings with the side chains on the N-atoms of the lactam groups of the TDPP moiety enabled the solubility and the solid-state spectroscopic properties of the resulting conjugated molecules to be tuned. Formation of nanostructured aggregates and dependence of their spectroscopic behavior on the substitution pattern were investigated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Aklalouch M.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Olivares-Marin M.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Lee R.-C.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Lee R.-C.,National Taiwan University | And 3 more authors.
ChemSusChem | Year: 2015

By comparing carbon electrodes with varying porosity in Li-O2 cells, we show that the effect of electrolyte stirring at a given current density can result in a change from 2D to 3D growth of discharged deposits. The change of morphology is evident using electron microscopy and by analyzing electrode pore size distribution with respect to discharge capacity. As a consequence, carbon electrodes with different textural properties exhibit different capacity enhancements in stirred-electrolyte cells. We demonstrate that mass transport can directly control the discharge mechanism, similar to the electrolyte composition and current density, which have already been recognized as determining factors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Calleja A.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Ricart S.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Granados X.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Palmer X.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | And 5 more authors.
CrystEngComm | Year: 2012

Electrospinning was used to produce fibers of barium zirconate (BZO) by metalorganic decomposition. Using short deposition times, a low density of randomly distributed fibers were deposited on lanthanum aluminate single crystals with (100) orientation. Then the films were subjected to thermal treatment at 600 °C and 800 °C to decompose the organic matter and crystallize the perovskite phase. X-ray diffraction, field-emission electron and atomic force microscopies were used as characterization tools. Continuous BZO tracks are obtained after removal of organics at 600 °C. At 800 °C, cube-on-cube heteroepitaxy of barium zirconate with respect to the lanthanum aluminate template was detected by synchrotron X-ray diffraction, although a fraction of misoriented BaZrO 3 crystals were also detected by grazing incidence X-ray diffraction (GIXRD). For precursor fibers closely attached to the single crystal surface, BaZrO 3 grows as epitaxial nanoparticles, which then coarsen and self-organize along the fiber tracks, showing oscillations in the interparticle separation distance. Growth of the coarsened low-aspect ratio crystals follows an anisotropic atomic diffusion mechanism, in which mass transport mainly occurs in the direction of the initially deposited fiber. The misoriented nanoparticles observed by GIXRD are attributed to the fibers deposited on top of those arriving first to the substrate and to the loss of the interfacial epitaxial growth at large crystal thickness. The distribution and morphology of the particles have been further analyzed by means of atomic force microscopy. © The Royal Society of Chemistry 2012.


Roa J.J.,University of Poitiers | Jimenez-Pique E.,Universidad Politécnica de Ingeniería | Diaz J.,University of Barcelona | Morales M.,University of Barcelona | And 2 more authors.
Surface and Coatings Technology | Year: 2012

The early stages of aggressive degradation at 85% of humidity for 24h of single crystals of YBa 2Cu 3O 7-δ textured by Bridgman technique have been analyzed by means of atomic force microscopy, X-ray photoelectron spectroscopy, nanoindentation and focused ion beam. The results show that the initial formation of barium hydroxide and the non-superconducting green phase, Y 2BaCuO 5, induces the surface degradation and the loss of the mechanical properties as a consequence of the mechanical transformation after the degradation process due to an embrittlement of the superficial layer. © 2012 Elsevier B.V.


Aklalouch M.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Calleja A.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Granados X.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Ricart S.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | And 4 more authors.
Solar Energy Materials and Solar Cells | Year: 2014

Fresnel lenses made of polymethylmethacrylate (PMMA) represent a cost-effective approach for concentrated photovoltaic (CPV) panels. The lens must sustain suitable working performance during the whole lifetime of the photovoltaic plant, as UV photodegradation is the main issue to be avoided. In this work, PMMA sheets were covered with a hybrid organic-inorganic sol-gel coating consisting of a matrix of an organically modified silicate (ORMOSIL) in which CeO2 nanoparticles 10-20 nm in size were dispersed, acting as the UV-absorbing agent. Ceria contents up to 40% w/w were studied and blended with the precursor ORMOSIL solution before deposition and in-situ polymerization at 80 C. The UV-visible spectra were analyzed between 200 and 800 nm. Furthermore, the effect of the aging on outdoor weathering was investigated for the coated PMMA sheets and compared to the unprotected sample. The results show that a load of 30% w/w of ceria nanoparticles provides a reasonable compromise in terms of UV protection and absorption in the visible range. The weathering test also demonstrates enhanced protection against UV degradation for the coated PMMA sheet compared to the bare substrate, although the adherence should be further improved for optimum performance. © 2013 Elsevier B.V.


Calleja A.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Calleja A.,OXOLUTIA SL Edifici Eureka | Ricart S.,Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas | Aklalouch M.,OXOLUTIA SL Edifici Eureka | And 3 more authors.
Journal of Sol-Gel Science and Technology | Year: 2014

Zr-doped ceria thin films were prepared by spin-coating metalorganic solutions containing polyvinylpyrrolidone (PVP), which serves as a relaxing agent to relieve the strong mechanical stresses developed during the thermal decomposition step. The precursor solutions were deposited on silicon substrates and subsequently heated in air at 500 °C. The complete decomposition of organics was checked by infrared spectroscopy with attenuated total reflectance. The molar ratio between PVP and total metal ions was varied between zero and one. Furthermore, the effect of using two different PVP molecular weights was also investigated. For the high molecular weight of PVP, crack-free films as high as 150 nm could be obtained compared to 30 nm when no PVP is added. Thickness after spin-coating and after thermal decomposition were determined by profilometry and correlated with the polymer concentration in the precursor solution, showing a linear dependence with PVP concentration in both cases. The main controlling parameter of the final thickness is the viscosity, with similar power law dependencies both before and after thermal treatment, which would indicate that the porosity fraction remains essentially constant in the final films. Furthermore, AFM analysis was used to investigate the flatness and surface porosity of the films after the thermal treatment. © 2014 Springer Science+Business Media New York.

Loading Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas collaborators
Loading Institute Of Ciencia Of Materials Of Barcelona Consejo Superior Of Investigaciones Cientificas collaborators