Editing Garnet (section)

==Synthetic garnets==
Also known as rare-earth garnets.

The crystallographic structure of garnets has been expanded from the prototype to include chemicals with the general formula ''A''<sub>3</sub>''B''<sub>2</sub>(''C''O<sub>4</sub>)<sub>3</sub>.  Besides silicon, a large number of elements have been put on the ''C'' site, including [[germanium]], [[gallium]], [[aluminum]], [[vanadium]] and [[iron]].<ref>S. Geller ''Crystal chemistry of the garnets'' Zeitschrift für Kristallographie, '''125'''(125), pp. 1–47 (1967) {{doi|10.1524/zkri.1967.125.125.1}}</ref>

[[Yttrium aluminium garnet]] (YAG), Y<sub>3</sub>Al<sub>2</sub>(AlO<sub>4</sub>)<sub>3</sub>, is used for [[Chemical synthesis|synthetic]] gemstones. Due to its fairly high refractive index, YAG was used as a diamond simulant in the 1970s until the methods of producing the more advanced simulant [[cubic zirconia]] in commercial quantities were developed. When doped with [[neodymium]] (Nd<sup>3+</sup>), [[erbium]] or [[gadolinium]] YAG may be used as the [[lasing medium]] in [[Nd:YAG laser]]s,<ref>{{Cite book|last=Yariv|first=Amnon|title=Quantum Electronics|publisher=Wiley|year=1989|isbn=978-0-471-60997-1|edition=3rd|pages=208–211}}</ref> [[Er:YAG laser]]s and [[Gadolinium yttrium garnet|Gd:YAG lasers]] respectively. These doped YAG lasers are used in medical procedures including [[laser skin resurfacing]], dentistry, and ophthalmology.<ref>{{Cite journal|last1=Teikemeier|first1=G|last2=Goldberg|first2=DJ|date=1997|title=Skin resurfacing with the erbium:YAG laser|journal=Dermatologic Surgery|location=Philadelphia|publisher=Lippincott Williams & Wilkins|volume=23|issue=8|pages=685–687|doi=10.1111/j.1524-4725.1997.tb00389.x|pmid=9256915|s2cid=31557815}}</ref><ref>{{Cite journal|last=Bornstein|first=E|date=2004|title=Proper use of Er:YAG lasers and contact sapphire tips when cutting teeth and bone: scientific principles and clinical application|journal=Dentistry Today|volume=23|issue=83|pages=86–89|pmid=15354712}}</ref><ref>{{Cite journal|last1=Kokavec|first1=Jan|last2=Wu|first2=Zhichao|last3=Sherwin|first3=Justin C|last4=Ang|first4=Alan JS|last5=Ang|first5=Ghee Soon|date=2017-06-01|title=Nd:YAG laser vitreolysis versus pars plana vitrectomy for vitreous floaters|journal=The Cochrane Database of Systematic Reviews|volume=2017|issue=6|pages=CD011676|doi=10.1002/14651858.CD011676.pub2|issn=1469-493X|pmc=6481890|pmid=28570745}}</ref>

Interesting magnetic properties arise when the appropriate elements are used. In [[yttrium iron garnet]] (YIG), Y<sub>3</sub>Fe<sub>2</sub>(FeO<sub>4</sub>)<sub>3</sub>, the five iron(III) ions occupy two [[octahedral]] and three [[tetrahedral]] sites, with the yttrium(III) ions coordinated by eight oxygen ions in an irregular cube. The iron ions in the two coordination sites exhibit different [[Spin (physics)|spins]], resulting in [[magnetic]] behavior. YIG is a [[Ferrimagnetism|ferrimagnetic]] material having a [[Curie point|Curie temperature]] of 550&nbsp;[[Kelvin|K]]. Yttrium iron garnet can be made into [[YIG sphere]]s, which serve as magnetically tunable [[Signal processing|filters]] and [[resonators]] for [[microwave]] frequencies.<ref>{{Cite web |title=What is YIG and How Does It Work So Well? |url=https://www.microlambdawireless.com/updates/what-is-yig-and-why-does-it-work-so-well/ |access-date=2023-07-17 |website=www.microlambdawireless.com}}</ref>

[[Lutetium aluminium garnet]] (LuAG), {{chem2|Al5[[Lutetium|Lu3]]O12}}, is an inorganic compound with a unique crystal structure primarily known for its use in high-efficiency laser devices. LuAG is also useful in the synthesis of [[transparent ceramics]].<ref>{{Cite journal|last=Moore|first=Cheryl|date=2015|title=Towards a Greater Understanding of Hydrothermally Grown Garnets and Sesquioxide Crystals for Laser Applications|journal=Clemson University Tiger Prints|bibcode=2015PhDT.......308M}}</ref> LuAG is particularly favored over other crystals for its high density and thermal conductivity; it has a relatively small [[lattice constant]] in comparison to the other [[Rare-earth element|rare-earth]] garnets, which results in a higher density producing a crystal field with narrower linewidths and greater energy level splitting in absorption and emission.<ref>{{Cite web|title=Lutetium Aluminum Garnet - LuAG - Lu3Al5O12|url=http://scientificmaterials.com/products/luag_Lu3Al5O12_lutetium_aluminum.php|access-date=2016-04-29|website=scientificmaterials.com}}</ref>

[[Terbium gallium garnet|Terbium gallium garnet (TGG)]], {{chem2|[[Terbium|Tb3]]Ga5O12}}, is a [[Faraday rotator]] material with excellent transparency properties and is very resistant to laser damage. TGG can be used in [[optical isolator]]s for laser systems, in [[optical circulator]]s for fiber optic systems, in [[optical modulator]]s, and in current and [[magnetometer|magnetic field]] sensors.<ref>{{Cite journal|last1=Majeed|first1=Hassaan|last2=Shaheen|first2=Amrozia|last3=Anwar|first3=Muhammad Sabieh|date=2013|title=Complete Stokes polarimetry of magneto-optical Faraday effect in a terbium gallium garnet crystal at cryogenic temperatures|url=https://www.osapublishing.org/captcha/(S(rogajdpzcsrcfvq3qgqu45d0))/?guid=70569AD2-E129-C404-B892-854EC43AA69E|journal=Optics Express|location=Washington, D.C.|publisher=The Optical Society|volume=21|issue=21|pages=25148–25158|doi=10.1364/OE.21.025148|pmid=24150356|bibcode=2013OExpr..2125148M|doi-access=free}}{{Dead link|date=May 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

Another example is [[gadolinium gallium garnet|gadolinium gallium garnet (GGG)]], {{chem2|[[Gadolinium|Gd3]]Ga2(GaO4)3}} which is synthesized for use as a substrate for liquid-phase epitaxy of magnetic garnet films for [[bubble memory]] and [[Photomagnetism|magneto-optical]] applications.{{Citation needed|date=February 2021}}