An investigation of the evaporation process of dielectric materials

Processes which take place during the evaporation and condensation of magnesium fluoride, cryolite and zinc sulfide were investigated by application of a mass spectrometer. It was found that MgF2 evaporates practically without decomposition but in the case of cryolite and ZnS dissociation and fractionating occur. In addition, mass spectrometrical results concerning the interactions of the evaporated materials with the residual gas of the vacuum chamber are reported. A preferred sorption of water vapour during the condensation of the fluorides was observed.