Dresden 2011 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 31: Nanostructures at surfaces: Dots, particles, clusters, arrays II

O 31.1: Vortrag

Dienstag, 15. März 2011, 11:15–11:30, WIL C107

Electrochemical preparation of Co-Ag nanostructured materials for GMR applications — •José Manuel García — University of Barcelona, Barcelona, Spain

Although giant magnetoresistance (GMR) phenomenon was discovered in sputtered Fe/Cr multilayers, some years later other configurations (i.e. granular films or nanowires) as well as other systems (i.e. Co/Cu, CoFe/Ag) were found to exhibit this property. Among those systems the Co-Ag system seems to be a good candidate as magnetoresistive material, because sharp magnetic/non-magnetic interfaces are expected in view of the total immiscibility between the two metals shown by the phase diagram. On the other hand, electrodeposition is a technique that day by day is gaining positions among the mainly employed physical methods for the preparation of thin films. This is due to the fact that electrodeposition shows some advantages over the physical techniques: versatility, selectivity, higher deposition rates and higher thicknesses, among others.

This work focuses on the preparation of different kinds of Co-Ag nanostructured materials with giant magnetoresistance. Granular films, multilayers and nanowires were prepared taking profit of the versatility of electrodeposition. Co(Core)-Ag(Shell) nanoparticles were also prepared but by a chemical method. The interest was to compare the properties of the Co-Ag materials obtained under the different configurations. In all cases, the experimental conditions were optimized in order to obtain the highest magnetoresistance values as possible and trying to share light on the mechanism responsible of GMR.