Powerful new superconducting generators, cables and fault current limiters are key systems which will enhance the efficiency and reliability of electricity generation, transport and distribution. The symposium will offer a close look at recent developments in superconducting materials and devices that demonstrate their significant benefit for power systems.
A. Llordes, K. Zalamova, S. Ricart, A. Palau, A. Pomar, T. Puig, A. Hardy, M. K. Van Bael and X. Obradors
Chem. Mat. 22, 1686-1694 (2010)
DOI: 10.1021/cm903080k
A thorough analytical study on the thermal decomposition evolution of the metal-trifluoroacetate precursor toward high-performance YBa2Cu3O7 superconducting films is presented. Evolved gas analysis (EGA), using Fourier transform infrared spectroscopy (FTIR) and mass spectrometry (MS), as well as X-ray diffraction (XRD), was performed to determine the complete chemical decomposition reaction of the metal-trifluoroacetate precursors. It is noteworthy that, contrary to what had been previously described, HF was not detected in the released gas. Moreover, we present new processing conditions that successfully reduced and even eliminated the undesirable porosity of the pyrolyzed films. Focused-ion-beam (FIB) studies demonstrated that the formation of pores was related to a fast escape of the released gas during precursor decomposition. The oxygen partial pressure was determined to be a key parameter to control both the kinetics and thermodynamics of the decomposition reaction and, hence, the porosity. This is of great importance because dense films are required to achieve high critical current densities in YBa2Cu3O7 superconducting films.
Title: Nous materials: una porta a la sostenibilitat
Authors: X. Obradors
Conference Name: CosmoCaixa, Cicle Del residu a la matèria primera: Les arrels dels productes de consum del demà
Place: Barcelona (Spain)
Date: October 2010
Title: Nanotecnología: reinventando la electricidad y la electrónica
Authors: X. Obradors
Conference Name: Museo de la Ciencia y la tecnología, Ciclo Conferencias Consolider, MICINN
Place: Madrid (Spain)
Date: November 2010
Title: Tecnología Superconductora para la Fusión
Authors: X. Obradors
Conference Name: Jornada XaRMAE sobre Fusión
Place: Barcelona (Spain)
Date: November 2010
Inventors: X. Obradors; T. Puig; S. Ricart; A. Pomar; F. Sandiumenge; N. Mestres; A. Llordés; M. Gibert; J. Gutiérrez; J. Gázquez; N. Romá
Title: Nanostructured superconducting material of type REBa2Cu3O7 (RE=rare earth or yttrium) with a high density of vortex anchoring centres and preparation method thereof
Application number: 200603172
Title: Energía nanotecnològica, Ciclo “Energía: hoy y mañana”
Authors: X. Obradors
Conference Name: Residencia Investigadores CSIC
Place: Barcelona
Date: February 2009
Title: Superconductividad: del exotismo cuántico, a la nanociencia y al megavatio
Authors: T. Puig
Conference Name: Encuentro sobre fronteras de la ciencia, “tiempo de física”, Fundación Duques de Soria
Place: Salamanca, Spain
Date: February 2009
Title: Nanotecnologia per aturar el canvi climàtic
Authors: X. Obradors
Conference Name: Auditori Caixa Manresa
Place: Manresa
Date: June 2009
Title: Recerca i estratègies de futur en el camp dels materials superconductors
Authors: T. Puig
Conference Name: Jornada XaRMAE en Recerca actual i estrategia de futur en el camp dels materials per a l’energia
Place: Barcelona, Spain
Date: November 2009
T. Puig, J. Gutierrez, A. Pomar, A. Llordes, J. Gazquez, S. Ricart, F. Sandiumenge and X. Obradors
Supercond. Sci. Technol. 21, 034008 (2008)
DOI:10.1088/0953-2048/21/3/034008
A methodology of general validity to study vortex pinning in YBa2Cu3O7−δ (YBCO) is described. It is based on measuring the angular-dependent critical current density in a large range of temperatures and magnetic fields and it permits one to identify, separate and quantify the three basic vortex pinning contributions associated to anisotropic–strong, isotropic–strong and isotropic–weak pinning centers. The corresponding vortex pinning phase diagrams for these three contributions are built up. This methodology is applied to the recently discovered solution-derived YBCO–BaZrO3 nanocomposites which display a maximum vortex pinning force of 78 GN m−3 at 65 K, being five times larger than that of NbTi at 4.2 K. These nanocomposites show an effective anisotropy tending to unity and the best superconducting properties observed so far in YBCO. We present the richness and complexity of their microstructure and the correlation with the vortex pinning properties. The application of the vortex pinning methodology and comparison with a standard solution-derived YBCO film enable us to identify the isotropic–strong defect contribution being at the origin of their unique properties.
