has a very broad transmission range from VUV to FIR and is used as window and substrate material. Compared to MgF2
it has an isotropic structure, lower hardness and is sensitive to thermal shocks.
If the condensation of water vapor is prevented, CaF2
windows can be used for several years in the laboratory.
begins to soften at 600 °C, the reaction with atmospheric moisture will take place above this temperature.