Laser-heating facility for diamond anvil cells

点击翻译按钮获取中文摘要

We propose to build a central CO2-laser heating facility for diamond anvil cell experiments in Frankfurt. The planned set-up would allow to heat transparent samples without addition of opaque absorbers. The projects of at least 10 groups rely on the availability of this facility. One set of experiments is aimed at studying temperature-dependent phase transformations, including melting, at high pressures. Specifically for the refractory compounds studied in the majority of projects, temperatures significantly higher than 2500 C are required. Furthermore, the laser heating facility would be employed to anneal samples to remove stress induced by the application of pressure. This is an important prerequisite to allow in situ (P only) diffraction experiments, as stress broadening will generally prevent the possibility to Rietveld-refine powder data. Several groups will require the laser-heating facility to synthesize novel compounds at extreme conditions. It is also planned that the laser heating will be used to develop new synthesis techniques such as self-propagating high-temperature synthesis (SHS) under high pressures. In addition to these scientific tasks, the central facility will allow us to train young researchers, perform prelimenary experiments in preparation of synchrotron-based experiments, test concepts for the planned high-pressure set-up at PETRA III and improve the experimental approach, e.g. by testing new shapes for the diamonds.