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Conventional solid state synthesis is based on reacting solids which, even after intense milling, are dispersed on a macroscopic scale compared to atomic distances. As a consequence, solid state reactions require a high thermal activation, favoring the formation of thermodynamically stable products. One option for straight forwardly overcoming these complications is to reduce the transport distances to atomic dimensions. This idee is realized with our new synthesis method ´Low-Temperature - Atomic Beam Deposition` (LT-ABD), which allow to disperse the components of the desired product at an atomic level and in an appropriate ratio. Such randomly 'frozen' mixtures of atoms could serve as an ideal starting point for solid state syntheses from atoms. The samples are in-situ investigated by an adequate X-ray diffractometer as a function of temperature. For synthesis, several UHV-preparation chambers are available with a special cart-system, which allows sample transfer maintaining vacuum and cooling. The synthesis method is closely connected to the theoretical work in the department, in particular with the global exploration of the energy landscape of chemical systems, to realize the predicted (meta)stable compounds experimentally. |
