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

substance Substance may refer to: * Matter, anything that has mass and takes up space Chemistry * Chemical substance, a material with a definite chemical composition * Drug, a chemical agent affecting an organism Arts, entertainment, and media Music * ' ...

. The

thermal conductivity The thermal conductivity of a material is a measure of its ability to heat conduction, conduct heat. It is commonly denoted by k, \lambda, or \kappa and is measured in W·m−1·K−1. Heat transfer occurs at a lower rate in materials of low ...

of yttrium oxide is 27 W/(m·K).

Applications

Phosphors

Yttrium Yttrium is a chemical element; it has Symbol (chemistry), symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost a ...

oxide 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 active laser medium, 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 ...

material. In particular, lasers with

ytterbium Ytterbium is a chemical element; it has 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. Like the other lanthani ...

dopant A dopant (also called a doping agent) is a small amount of a substance added to a material to alter its physical properties, such as electrical or optics, optical properties. The amount of dopant is typically very low compared to the material b ...

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 aluminium garnet Yttrium aluminium garnet (YAG, Yttrium, Y3Aluminium, Al5Oxygen, O12) is a synthetic crystalline material of the garnet group. It is a Crystal system, cubic yttrium aluminium oxide phase, with other examples being YAlO3 (YAP) in a Crystal system, ...

, 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 zirconium silicate or zircon), is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the mineral ba ...

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 which has been stabilized with the addition of yttrium oxide. 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 shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...

filters.

Superconductors

Y₂O₃ is used to make the high temperature superconductor 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 or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

and

ammonium chloride Ammonium chloride is an inorganic chemical compound with the chemical formula , also written as . It is an ammonium salt of hydrogen chloride. It consists of ammonium cations and chloride anions . It is a white crystalline salt (chemistry), sal ...

High-temperature coatings

Y₂O₃ is used in specialty coatings and pastes that can withstand high temperatures and act as a barrier for reactive metals such as uranium.

Heat radiators

NASA developed a material it dubbed Solar White that it is exploring for use as a radiator in deep space, where it is expected to reflect more than 99.9% of the sun’s energy (low solar radiation absorption and high infrared emittance). A sphere covered with a 10 mm coating sited far from the Earth and 1

astronomical unit The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its m ...

from the sun could keep temperatures below 50 K. One use is long-term cryogenic storage.

Optical Industry

It's also used to create red

for LED screens and TV tubes, as well as in anti-reflective coatings to enhance light transmission.

Natural occurrence

Yttriaite-(Y), 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 (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a metal found naturally on Earth almost exclusively in compounds with other elements. It was identified as a distinct element in 1781 and first ...

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 language, Spanish word ''placer'', meaning "alluviu ...

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

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

. 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 the ...

, near

Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

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

References

External links

Yttrium oxide information at Webelements
{{Authority control Yttrium compounds Sesquioxides Transition metal oxides Crystals in space group 206