Zirconia

Zirconium Dioxide

Zirconium dioxide is one of the most studied ceramic materials. Pure ZrO2 has a monoclinic crystal structure at room temperature and transitions to tetragonal and cubic at increasing temperatures. The volume expansion caused by the cubic to tetragonal to monoclinic transformation induces very large stresses, and will cause pure ZrO2 to crack upon cooling from high temperatures. Several different oxides are added to zirconia to stabilize the tetragonal and/or cubic phases: magnesium oxide (MgO), yttrium oxide, (Y2O3), calcium oxide (CaO), and cerium(III) oxide (Ce2O3), amongst others. Zirconia is a unique advanced ceramic. Zirconia powder exhibits superior mechanical properties such as high strength and flexibility. Heat insulating properties and oxygen-ion conductivity indicate zirconia has potential for use in a wide variety of applications - everything from telecommunications to the new energy of the future and environmentally beneficial products.
 * Zirconium dioxide** ( ZrO2 ), sometimes known as **zirconia** (not to be confused with zircon), is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the rare mineral baddeleyite. The high temperature cubic crystalline form is rarely found in nature as mineral tazheranite (Zr,Ti,Ca)O2 (and a doubtful mineral arkelite). This form, also called cubic zirconia, is synthesized in various colours for use as a gemstone and a diamond simulant.

It can be used to thermally conduct which has led to its use as a thermal barrier coating. It can be used for crowns in teeth. Visually discerning a good quality cubic zirconia from a diamond is difficult and so zirconia is often used in jewelry.
 * Uses:**
 * ~ Properties ||
 * Molecular formula || ZrO2 ||
 * Molar mass || 123.218 g/mol ||
 * Appearance || white powder ||
 * Density || 5.68 g/cm3 ||
 * Melting point || 2715 °C ||
 * Boiling point || 4300 °C ||
 * Solubility in water || negligible ||
 * Solubility || soluble in HF, and hot H2SO4, HNO3, HCl ||
 * Refractive index (//n//D) || 2.13 ||