The main use of zirconia is in the production of ceramics,[8][9] with other uses including as a protective coating on particles of titanium dioxide pigments,[1] as a refractory material, in insulation, abrasives and enamels. Stabilized zirconia is used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. This high ionic conductivity (and a low electronic conductivity) makes it one of the most useful electroceramics.[1] Zirconium dioxide is also used as the solid electrolyte in electrochromic devices.
yttrium oxide (Y2O3, yttria), calcium oxide (CaO), and cerium(III) oxide (Ce2O3).