Entity

Time filter

Source Type


Picher M.,Montpellier University | Anglaret E.,Montpellier University | Arenal R.,ONERA | Arenal R.,Institute Nanociencia Of Aragon Ina | Jourdain V.,Montpellier University
ACS Nano | Year: 2011

Single-walled carbon nanotubes are grown by catalytic chemical vapor deposition in various conditions of temperature and carbon precursor pressure. Systematic analyses of the Raman radial breathing modes at two laser wavelengths are used to monitor the evolution of the diameter distribution. Two distinct domains with opposite influences of the temperature and the precursor pressure on the diameter distribution are evidenced. Thanks to specially designed experiments made of two successive growths, three processes are identified to influence the diameter distribution during the nanotube growth: (i) at too low precursor pressure, nanotube nucleation cannot occur on the smallest catalyst particles; (ii) at low temperature and high precursor pressure, small catalyst particles are preferably encapsulated by disordered carbon structures; (iii) at high temperature, catalyst coarsening causes the disappearance of the smallest catalyst particles. © 2011 American Chemical Society. Source


Gomez V.,Institute Nanociencia Of Aragon Ina | Alguacil F.J.,CSIC - National Center for Metallurgical Research | Alonso M.,CSIC - National Center for Metallurgical Research
Aerosol and Air Quality Research | Year: 2012

Experimental characterization of a mixed screen-type diffusion battery has been made by using monodisperse neutral particles with diameter below 10 nm. The diffusion battery contained two "composite" grids, each of them consisting of a gold screen sandwiched between two Aluminium screens. The equivalent fiber diameter of the composite grid was obtained by fitting the experimental penetration data for uncharged particles to the Cheng-Yeh model. Once the equivalent or effective fiber diameter is known, the fan filter model of Cheng and Yeh allows accurate prediction of particle penetration through the mixed-screen type diffusion battery. © Taiwan Association for Aerosol Research. Source


Gomez V.,Institute Nanociencia Of Aragon Ina | Huang C.H.,Yuanpei University | Alguacil F.J.,CSIC - National Center for Metallurgical Research | Alonso M.,CSIC - National Center for Metallurgical Research
Aerosol and Air Quality Research | Year: 2012

Experimental characterization of a mixed screen-type diffusion battery has been made by using monodisperse neutral particles with diameter below 10 nm. The diffusion battery contained two "composite" grids, each of them consisting of a gold screen sandwiched between two aluminum screens. The equivalent fiber diameter of the composite grid was obtained by fitting the experimental penetration data for uncharged particles to the Cheng-Yeh model. Once the equivalent or effective fiber diameter is known, the fan filter model of Cheng and Yeh allows accurate prediction of particle penetration through the mixed-screen type diffusion battery. © Taiwan Association for Aerosol Research. Source


Lacroix L.-M.,INSA Toulouse | Gatel C.,CEMES | Arenal R.,Institute Nanociencia Of Aragon Ina | Garcia C.,INSA Toulouse | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2012

A platinum star performance: Quasi-single-crystalline Pt nanoparticles with peculiar morphologies cubic dendrites, planar tripods, and fivefold stars were synthesized in high yield. Shape selectivity was achieved by finely tuning the growth kinetics under a dihydrogen atmosphere. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Rivas-Murias B.,University of Santiago de Compostela | Lucas I.,University of Zaragoza | Jimenez-Cavero P.,University of Zaragoza | Magen C.,University of Zaragoza | And 3 more authors.
Nano Letters | Year: 2016

We report the effect of interface symmetry-mismatch on the magnetic properties of LaCoO3 (LCO) thin films. Growing epitaxial LCO under tensile strain on top of cubic SrTiO3 (STO) produces a contraction along the c axis and a characteristic ferromagnetic response. However, we report here that ferromagnetism in LCO is completely suppressed when grown on top of a buffer layer of rhombohedral La2/3Sr1/3MnO3 (LSMO), in spite of identical in-plane and out-of-plane lattice deformation. This confirms that it is the lattice symmetry mismatch and not just the total strain, which determines the magnetism of LCO. On the basis of this control over the magnetic properties of LCO, we designed a multilayered structure to achieve independent rotation of the magnetization in ferromagnetic insulating LCO and half-metallic ferromagnet LSMO. This is an important step forward for the design of spin-filtering tunnel barriers based on LCO. © 2016 American Chemical Society. Source

Discover hidden collaborations