INVESTIGADORES
LUCCAS Roberto FabiÁn
congresos y reuniones científicas
Título:
Flux pinning in YBCO films with artificial model nanostructures
Autor/es:
A. PALAU; C. MONTON; R. F. LUCCAS; T. PUIG; X. GRANADOS; X. OBRADORS
Lugar:
Dresden
Reunión:
Congreso; EUCAS2009; 2009
Institución organizadora:
EUCAS
Resumen:
Understanding vortex pinning mechanisms and correspondingly the interaction between vortices and defects is still one of the major goals to enhance properties of superconducting materials. Therefore, the capability to artificially nanostructure superconducting materials using model systems to enhance vortex pinning is one of the major topics nowadays.We have used high resolution nanolithography techniques (Focused Ion Beam, Electron Beam Lithography and nanoindentation) in order to create artificial pining sites in YBCO films grown by chemical methods. Model systems with different geometry, distribution and density of nano-defects have been studied.The artificial pinning structures have been designed to compete with natural defects (dislocations, low angle grain boundaries, twin boundaries, stacking faults, random defects) which intrinsically produce strong pinning in YBCO films. Angular critical current measurements have been performed in a wide temperature and magnetic field range in order to study the different vortex pinning contributions in different nanostructured YBCO films, demonstrating that critical currents can increase depending on the nanostructured model systems analysed. Moreover, the interaction vortex-defect at low magnetic fields has been explored by means of magnetic decoration. The elastic energy of the vortex lattice has been calculated on the decorated images and the pinning contribution from the artificial defects determined.