Actinide Thin Films as Surface Models

Reducing the dimensionality of a material can effectively influence its properties. Compared to the knowledge on actinide bulk materials concerning structure, behaviour and reactivity much less is known for the materials with reduced dimensions (thin films, colloids, nanoparticles, clusters, isolated atoms in a matrix). The surface science laboratory installations at the Institute for Transuranium Elements (ITU) provide the combination of a reactive sputter deposition set-up for thin film production with photoemission spectroscopy instrumentation. This allows characterizing the thin film materials surface elemental composition, to draw conclusions on chemical environment of the constitutive elements and to gather information on the electronic structure of the materials. In this contribution we focus on the investigation of surface reactions but also some examples are given to show how the electronic structure of 5f materials is influenced by reducing the materials dimensions. Additional characterisation methods are applied to show that the films can also serve as structural models: characterisation of the film surfaces by SEM-EDX (Scanning electron microscopy combined with X-ray spectroscopy) and AFM (Atomic force microscopy) are carried out. For bulk characterisation X-Ray diffraction (XRD) is used to give insight in crystallinity. The designed thin film models are used in gas adsorption [4,5] (O2, Oatom, H2, Hatom) and electrochemical experiments probing their redox behaviour. Specific examples are presented to illustrate this approach to mechanistic understanding.

SEIBERT Alice;  STUMPF Silvia;  GOUDER Thomas;  SCHILD D.;  DENECKE M. A.; 

2013-02-26

Springer Verlag Berlin, Heidelberg

JRC58228

978-3-642-11431-1,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC58228,   

10.1007/978-3-642-11432-8_10,