High temperature electrolysis with solid oxide electrolyser cells has also been proposed to produce oxygen on Mars from atmospheric carbon dioxide, using zirconia electrolysis devices.
These caps are made from number of different materials e.g. Kel-F, Vespel, zirconia or boron nitride depending on the application required.
This phase is thermodynamically unstable at room temperature with respect to the binary oxides synthesised by heating stoichiometric quantities of these oxides together and then quenching the material by rapidly cooling it from approximately 900 °C to room temperature.