Yttrium oxide, also known as yttria, is Y₂ O₃. It is an air-stable, white solid substance. The

thermal conductivity The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal ...

of yttrium oxide is 27 W/(m·K).

Uses

Phosphors

Yttria is widely used to make Eu:YVO₄ and Eu:Y₂O₃

phosphors A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or v ...

that give the red color in color TV picture tubes.

Yttria lasers

Y₂O₃ is a prospective

solid-state laser A solid-state laser is a laser that uses a gain medium that is a solid, rather than a liquid as in dye lasers or a gas as in gas lasers. Semiconductor-based lasers are also in the solid state, but are generally considered as a separate class from ...

material. In particular, lasers with

ytterbium Ytterbium is a chemical element with the symbol Yb and atomic number 70. It is a metal, the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state. However, like the othe ...

dopant A dopant, also called a doping agent, is a trace of impurity element that is introduced into a chemical material to alter its original electrical or optical properties. The amount of dopant necessary to cause changes is typically very low. When ...

allow the efficient operation both in continuous operation and in pulsed regimes. At high concentration of excitations (of order of 1%) and poor cooling, the quenching of emission at laser frequency and avalanche broadband emission takes place. (Yttria-based lasers are not to be confused with YAG lasers using

yttrium aluminum garnet Yttrium aluminium garnet (YAG, Y3 Al5 O12) is a synthetic crystalline material of the garnet group. It is a cubic yttrium aluminium oxide phase, with other examples being YAlO3 (YAP) in a hexagonal or an orthorhombic, perovskite-like form, and ...

, a widely used crystal host for rare earth laser dopants).

Gas Lighting

The original use of the mineral yttria and the purpose of its extraction from mineral sources was as part of the process of making gas mantles and other products for turning the flames of artificially-produced gases (initially hydrogen, later coal gas, paraffin, or other products) into human-visible light. This use is almost obsolete - thorium and cerium oxides are larger components of such products these days.

Dental ceramics

Yttrium oxide is used to stabilize the

Zirconia Zirconium dioxide (), 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 mineral baddeleyite. A dopant stabi ...

in late-generation porcelain-free metal-free dental ceramics. This is a very hard ceramic used as a strong base material in some full ceramic restorations. The zirconia used in dentistry is

zirconium oxide Zirconium dioxide (), 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 mineral baddeleyite. A dopant stabi ...

which has been stabilized with the addition of

yttrium oxide Yttrium oxide may refer to: * Yttrium(II) oxide, YO, a dark brown solid * Yttrium(III) oxide Yttrium oxide, also known as yttria, is Y2 O3. It is an air-stable, white solid substance. The thermal conductivity of yttrium oxide is 27 W/(m·K). ...

. The full name of zirconia used in dentistry is "yttria-stabilized zirconia" or YSZ.

Microwave filters

Yttrium oxide is also used to make

yttrium iron garnet Yttrium iron garnet (YIG) is a kind of synthetic garnet, with chemical composition , or Y3Fe5O12. It is a ferrimagnetic material with a Curie temperature of 560 K. YIG may also be known as yttrium ferrite garnet, or as iron yttrium oxide or ...

s, which are very effective

microwave Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...

filters.

Superconductors

Y₂O₃ is used to make the

high temperature superconductor High-temperature superconductors (abbreviated high-c or HTS) are defined as materials that behave as superconductors at temperatures above , the boiling point of liquid nitrogen. The adjective "high temperature" is only in respect to previ ...

YBa₂Cu₃O₇, known as "1-2-3" to indicate the ratio of the metal constituents: : 2 Y₂O₃ + 8 BaO + 12 CuO + O₂ → 4 YBa₂Cu₃O₇ This synthesis is typically conducted at 800 °C.

Inorganic synthesis

Yttrium oxide is an important starting point for inorganic compounds. For organometallic chemistry it is converted to YCl₃ in a reaction with concentrated

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid Acid strength is the tendency of an acid, symbol ...

and ammonium chloride.

Natural occurrence

Yttriaite-(Y) Yttriaite-(Y) is an exceedingly rare mineral, a natural form of yttrium oxide, Y2O3.Mills, S.J., Kartashov, P.M., Ma, C., Rossman, G.R., Novgorodova, M.I., Kampf, A.R., and Raudsepp, M., 2011: Yttriaite-(Y): The natural occurrence of Y2O3 from the ...

, approved as a new mineral species in 2010, is the natural form of yttria. It is exceedingly rare, occurring as inclusions in native

tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolat ...

particles in a

placer deposit In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish word ''placer'', meaning "alluvial sand". Placer min ...

of the Bol’shaja Pol’ja () river, Prepolar

Ural Ural may refer to: *Ural (region), in Russia and Kazakhstan *Ural Mountains, in Russia and Kazakhstan *Ural (river), in Russia and Kazakhstan * Ual (tool), a mortar tool used by the Bodo people of India *Ural Federal District, in Russia *Ural econ ...

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...

. As a chemical component of other minerals, the oxide yttria was first isolated in 1789 by

Johan Gadolin Johan Gadolin (5 June 176015 August 1852) was a Finnish chemist, physicist and mineralogist. Gadolin discovered a " new earth" containing the first rare-earth compound yttrium, which was later determined to be a chemical element. He is also con ...

, from rare-earth minerals in a mine at the Swedish town of

Ytterby Ytterby () is a village on the Swedish island of Resarö, in Vaxholm Municipality in the Stockholm archipelago. Today the residential area is dominated by suburban homes. The name of the village translates to "outer village". Ytterby is perh ...

, near

Stockholm Stockholm () is the Capital city, capital and List of urban areas in Sweden by population, largest city of Sweden as well as the List of urban areas in the Nordic countries, largest urban area in Scandinavia. Approximately 980,000 people liv ...

.Mindat, http://www.mindat.org/min-40471.html

References

External links

Yttrium oxide information at Webelements
{{Authority control Yttrium compounds Sesquioxides Transition metal oxides