Using X-rays absorption to probe interfaces in surfaces and multicomponent

LISANDRO J. GIOVANETTI

Bariloche

Workshop; Segundo Workshop de Usuarios Argentinos de Técnicas de Luz Sincrotrón; 2013

Instituto Balseiro ? Centro Atómico Bariloche

Atoms at the surfaces of materials represent the frontier separating the bulk from the surrounding medium. Scientists have intensely studied the structure and properties of surfaces with the goal of understanding and improving the electronic and chemical properties of materials. The surface-medium interaction determines wetting, friction, chemical, biological, and electronic properties. The need to pursue studies in the ?normal environment? that surrounds a material has always been recognized, the techniques used in the past have only partially fulfilled this need, as many of them work best under high vacuum conditions, far for the normal condition needed to understand the phenomena under study. The use of synchrotron based techniques in order to elucidate the electronic structure of atoms at interfaces has gain a great impulse in the recent years, in particular with the emergence of third generation machines that provide higher flux in a focalized beam. This type of source allows performing for example X ray absorption experiments for almost any element in the periodic table and at in-situ condition even in a energy region that were limited to UHV conditions (C and O K edges for example) . Combination of this great flux with different detection modes and novel experimental setups gives possibility of get insight into the electronic structure of the different atoms that compose the interface with chemical selectivity and surface or bulk sensitivity. In this work we will present two examples of this type of approach applied to a flat metal surface and multicomponent nanoparticles for applications in Lithium ion batteries.