European Commission Joint Research Centre Institute for Transuranium Elements
Tel.: +49 (0)7247-951-0 E-mail
The surface region of actinides has two major interests. It is a region, where the electronic structure changes from the 3D solid state to lower dimensionality. Band narrowing occurs because of the lowered coordination, and this can push the 5f states into localization. Changed magnetic properties, mixed valence, etc. occur in that region. Surface effects are further investigated on thin films of chosen composition, thickness and morphology.
From a chemical point of view, the surface is the contact region between solid and its environment. Any material exchange takes place there and depends strongly on the properties of the surface. It plays an important role storage behaviour of nuclear waste. Assessment of the long term storage porperties requires a mechanistic knowledge of the surface reactions (corrosion, electrochemistry, leaching, etc) between the waste and its environment (ground-water) on a long time scale.
In both research domains, active control of the surface properties is achieved by in-situ preparation of thin films under well defined conditions. This is done by various deposition techniques, which together with photoelectron spectroscopy are the backbone of our activitiy.