[en] The growth of copper crystals on copper, by thermal decomposition of CuF₂, has been studied previously. It has been observed that, at a given temperature, the deposition rate reaches a maximum value which seems to be controlled only by the desorption of fluorine from a complete monolayer.Recent results concerning the thermal decomposition of TiF₄ and Ti and FeF₂ on Fe confirm this mechanism and give a measure of the heat of desorption of fluorine. The deposition rate can be generally improved if one uses the thermal decomposition of subfluorides. A method was developed based on sub-fluoride preparation in situ near the substrate. According to this new method, the formation of the sub-fluoride and its thermal decomposition occur simultaneously. This process is very suitable for the deposition of refractory metals at relatively low temperatures. Some examples are given, concerning mainly the decomposition of WF₅. Generally, in comparison with other halides, it seems that the thermal decomposition of fluorides is preferable for obtaining very high quality deposits, provided the technology necessary for fluorine chemistry is available

No abstract available

[en] An automatic liquid nitrogen feeding device has been developed (and used) in the framework of corrosion tests realized with constantly renewed uranium hexafluoride. The issue was to feed liquid nitrogen to a large capacity metallic trap in order to condensate uranium hexafluoride at the exit of the corrosion chambers. After having studied various available devices, a feeding device has been specifically designed to be robust, secure and autonomous, as well as ensuring a high liquid nitrogen flowrate and a highly elevated feeding frequency. The device, made of standard material, has been used during 4000 hours without any problem