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Revision as of 13:47, 31 July 2011 editSunadirE (talk | contribs)213 editsm →Safety: Typo← Previous edit		Latest revision as of 11:51, 17 November 2024 edit undoDMacks (talk | contribs)Edit filter managers, Autopatrolled, Administrators186,046 edits Bad ref (see WP:Articles for deletion/Beryllium chlorate, WT:CHEM#Heads-up regarding Richard Ropp, WT:CHEMS#Encyclopedia of the Alkaline Earth Compounds). Undid revision 1251878109 by Itz.mas10 (talk)Tag: Undo
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	{{Chembox		{{Chembox
			| Verifiedfields = changed
	| verifiedrevid = 404695937
			| Watchedfields = changed
	| ImageFile = Wurtzite polyhedra.png
			| verifiedrevid = 442353803
	| ImageFile_Ref = {{chemboximage|correct|??}}
			| ImageFile = Wurtzite polyhedra.png
	| ImageSize = 244
			| ImageFile_Ref = {{chemboximage|correct|??}}
	| ImageName = Unit cell ball and stick model of beryllium oxide
			| ImageName = Unit cell, ball and stick model of beryllium oxide
	| IUPACName = Beryllium oxide
			| ImageFile2 = BeO sample.jpg
	| SystematicName =
			| PIN = Beryllium(II) monoxide
	| OtherNames = Berlox<br />
			| SystematicName = Oxoberyllium
	Beryllia<br />
			| OtherNames = Beryllia, Thermalox, Bromellite, Thermalox 995.<ref>{{Cite web|title = beryllium oxide – Compound Summary|url = https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=14775&loc=ec_rcs|work = PubChem Compound|publisher = National Center for Biotechnology Information|access-date = 8 November 2011|location = USA|date = 27 March 2005|at = Identification and Related records}}</ref>
	Beryllia ceramic<br />
			| Section1 = {{Chembox Identifiers
	]<br />
			| CASNo = 1304-56-9
	Super beryllia<br />
			| CASNo_Ref = {{cascite|correct|CAS}}
	Thermalox
			| UNII_Ref = {{fdacite|correct|FDA}}
	| Section1 = {{Chembox Identifiers
	| CASNo = 1304-56-9		| UNII = 2S8NLR37S3
			| PubChem = 14775
	| CASNo_Ref = {{cascite|correct|CAS}}
	| PubChem = 14775		| ChemSpiderID = 14092
	| PubChem_Ref = {{Pubchemcite|correct|PubChem}}		| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
			| EINECS = 215-133-1
	| ChemSpiderID = 14092
			| UNNumber = 1566
	| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
			| MeSHName = beryllium+oxide
	| EINECS = 215-133-1
	| UNNumber = 1566		| ChEBI = 62842
			| ChEBI_Ref = {{ebicite|changed|EBI}}
	| MeSHName = Beryllium+oxide
	| RTECS = DS4025000		| RTECS = DS4025000
	| SMILES =		| Beilstein = 3902801
	| SMILES1 = =O		| SMILES = =
	| StdInChI = 1S/Be.O		| SMILES1 = #
			| StdInChI = 1S/Be.O
	| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
			| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
	| InChI = 1/Be.O/rBeO/c1-2
	| StdInChIKey = LTPBRCUWZOMYOC-UHFFFAOYSA-N		| InChI = 1/Be.O/rBeO/c1-2
			| StdInChIKey = LTPBRCUWZOMYOC-UHFFFAOYSA-N
	| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}		| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
	| InChIKey = LTPBRCUWZOMYOC-SRAGPBHZAE}}		| InChIKey = LTPBRCUWZOMYOC-SRAGPBHZAE
			}}
	| Section2 = {{Chembox Properties		| Section2 = {{Chembox Properties
	| Be = 1		| Be=1 | O=1
			| Appearance = Colourless, vitreous crystals
	| O = 1
			| Odor = Odourless
	| ExactMass = 25.007096757 g mol<sup>-1</sup>
			| Density = 3.01 g/cm<sup>3</sup><ref name=crc>], p. 4.51</ref>
	| Appearance = White crystals
	| Odor = Odourless		| MeltingPtC = 2578
			| MeltingPt_ref=<ref name=crc/>
	| Density = 3.02 g cm<sup>-3</sup><ref>{{RubberBible87th}}</ref>
	| MeltingPtC = 2507		| BoilingPtC =
	| BoilingPtC = 3900		| Solubility =
			| SolubleOther =
	| ThermalConductivity = 330 W/(m·K)
			| MagSus = −11.9·10<sup>−6</sup> cm<sup>3</sup>/mol<ref>], p. 4.126</ref>
	| BandGap = 10.6 eV
			| BandGap = 10.6 eV<ref>{{cite journal|doi=10.1063/1.2168040 |title=Wide-band gap oxide alloy: BeZnO |date=2006 |last1=Ryu |first1=Y. R. |last2=Lee |first2=T. S. |last3=Lubguban |first3=J. A. |last4=Corman |first4=A. B. |last5=White |first5=H. W. |last6=Leem |first6=J. H. |last7=Han |first7=M. S. |last8=Park |first8=Y. S. |last9=Youn |first9=C. J. |last10=Kim |first10=W. J. |journal=Applied Physics Letters |volume=88 |issue=5 |page=052103 |bibcode=2006ApPhL..88e2103R }}</ref>
	| RefractIndex = 1.7}}
			| RefractIndex = n<sub>1</sub>1.7184, n<sub>2</sub>=1.733<ref>], p. 10.248</ref><ref>. webmineral</ref>
	| Section3 = {{Chembox Structure
			| ThermalConductivity = 210 W/(m·K)<ref>], p. 12.222</ref>
	| CrystalStruct = hexagonal, ]
			}}
	| SpaceGroup = P6<sub>3</sub>/mc, No. 186
			| Section3 = {{Chembox Structure
	}}
			| Structure_ref=<ref>], p. 4.139</ref>
	| Section4 = {{Chembox Thermochemistry
			| CrystalStruct = Hexagonal, ]
	| Reference = <ref>{{CODATA thermo}}.</ref>
			| SpaceGroup = P6<sub>3</sub>mc
	| DeltaHf = –609.4(25) kJ mol<sup>−1</sup>
			| PointGroup = C<sub>6v</sub>
	| Entropy = 13.77(4) J K<sup>–1</sup> mol<sup>–1</sup>
			| MolShape = Linear
	}}
			| UnitCellFormulas = 2
	| Section7 = {{Chembox Hazards
			| LattConst_a = 2.6979 Å
	| EUClass = ]<br/>Highly toxic ('''T+''')<br />Irritant ('''Xi''')
			| LattConst_c = 4.3772 Å
	| EUIndex = 004-003-00-8
			}}
	| GHSPictograms = {{GHS06|Acte Tox. 2, Acute Tox. 3}}{{GHS08|Carc. 1B, STOT RE 1, STOT SE 3, Skin Sens. 1, Eye Irrit. 2, Skin Irrit. 2}}
			| Section4 = {{Chembox Thermochemistry
	| GHSSignalWord = DANGER
			| Thermochemistry_ref =<ref>], pp. 5.1, 5.6, 6.155</ref>
	| HPhrases = {{H-phrases|350|330|301|372|319|335|315|317}}
			| DeltaHf = −609.4±2.5 kJ/mol
			| DeltaGf = −580.1 kJ/mol
			| Entropy = 13.77±0.04 J/(K·mol)
			| HeatCapacity = 25.6 J/(K·mol)
			| DeltaHfus = 86 kJ/mol
			}}
			| Section5 = {{Chembox Hazards
			| MainHazards = Very toxic, Group 1B carcinogen
			| GHSPictograms = {{GHS skull and crossbones}} {{GHS health hazard}}{{GHS environment}}
			| GHSSignalWord = '''DANGER'''
			| HPhrases = {{H-phrases|301|315|317|319|330|335|350|372}}
			| PPhrases = {{P-phrases|201|260|280|284|301+310|305+351+338}}
	| NFPA-H = 4		| NFPA-H = 4
	| NFPA-F = 0		| NFPA-F = 0
	| NFPA-R = 0		| NFPA-R = 0
			| LD50 = 15 mg/kg (mouse, oral)<ref>Beryllium oxide toxicity</ref>
	| RPhrases = {{R49}}, {{R25}}, {{R26}}, {{R36/37/38}}, {{R43}}, {{R48/23}}
	| SPhrases = {{S53}}, {{S45}}
			| REL = Ca C 0.0005 mg/m<sup>3</sup> (as Be)<ref name=PGCH>{{PGCH|0054}}</ref>
	| FlashPt = Non-flammable
			| PEL = TWA 0.002 mg/m<sup>3</sup><br/>C 0.005 mg/m<sup>3</sup> (30 minutes), with a maximum peak of 0.025 mg/m<sup>3</sup> (as Be)<ref name=PGCH/>
	| LD50 = 2062 mg/kg (mouse, oral)
			| IDLH = Ca <ref name=PGCH/>
	}}		}}
	| Section8 = {{Chembox Related		| Section6 = {{Chembox Related
			| OtherCations = {{unbulleted list
	| OtherAnions = ]<br />]<br />]
	| OtherCations = ]<br />]		| ]
			| ]
			| ]
			| ]
	}}		}}
			| OtherAnions = ]
	}}		}}
			}}
	'''] oxide''' ('''BeO'''), also known as '''beryllia''', is an ] with the ] BeO. This white crystalline solid is notable as it is an electrical insulator with a thermal conductivity higher than any other non-metal except diamond, and actually exceeds that of some metals.<ref name = "Greenwood">{{Greenwood&Earnshaw}}</ref> Its high melting point leads to its use as a ].<ref>{{cite book|url=http://books.google.com/?id=6TKSG6LWIEQC&pg=PA301|page=301|author=Raymond Aurelius Higgins|year=2006|title=Materials for Engineers and Technicians|publisher=Newnes|isbn=0750668504}}</ref> It occurs in nature as the mineral ]. Historically beryllium oxide was called '''glucina''' or glucinium oxide.
			'''Beryllium oxide''' ('''BeO'''), also known as '''beryllia''', is an ] with the ] BeO. This colourless solid is an ] with a higher ] than any other non-metal except ], and exceeds that of most metals.<ref name = "Greenwood">{{Greenwood&Earnshaw}}</ref> As an ], beryllium oxide is white. Its high melting point leads to its use as a ] material.<ref>{{cite book |url=https://archive.org/details/materialsforengi0004higg |url-access=registration |page= |author=Higgins, Raymond Aurelius |year=2006 |title=Materials for Engineers and Technicians |publisher=Newnes |isbn=0-7506-6850-4}}</ref> It occurs in nature as the mineral ]. Historically and in ], beryllium oxide was called '''glucina''' or '''glucinium oxide''', owing to its sweet taste.
	==Preparation and chemical properties==		==Preparation and chemical properties==
	Beryllium oxide can be prepared by calcining (roasting) beryllium carbonate, dehydrating ] or igniting the metal:		Beryllium oxide can be prepared by ] (roasting) ], dehydrating ], or igniting metallic ]:
	:BeCO<sub>3</sub>→ BeO + CO<sub>2</sub>		:BeCO<sub>3</sub> → BeO + CO<sub>2</sub>
	:Be(OH)<sub>2</sub> → BeO + H<sub>2</sub>O		:Be(OH)<sub>2</sub> → BeO + H<sub>2</sub>O
	:2 Be + O<sub>2</sub> → 2 BeO		:2 Be + O<sub>2</sub> → 2 BeO
	Igniting beryllium in air gives a mixture of BeO and the nitride Be<sub>3</sub>N<sub>2</sub>.<ref name = "Greenwood"/>		Igniting beryllium in air gives a mixture of BeO and the nitride ].<ref name = "Greenwood"/> Unlike the oxides formed by the other Group 2 elements (]), beryllium oxide is ] rather than basic.
	Unlike oxides formed by the other group 2 (alkaline earth metals), beryllium oxide is ] rather than basic.
	Beryllium oxide formed at high temperatures (>800°C) is inert, but dissolves easily in hot aqueous ] (NH<sub>4</sub>HF<sub>2</sub/>) or a hot solution of concentrated ] (H<sub>2</sub>SO<sub>4</sub>) and ] ((NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>).		Beryllium oxide formed at high temperatures (>800&nbsp;°C) is inert, but dissolves easily in hot aqueous ] (NH<sub>4</sub>HF<sub>2</sub>) or a solution of hot concentrated ] (H<sub>2</sub>SO<sub>4</sub>) and ] ((NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>).
	==Structure==		==Structure==
	BeO adopts the hexagonal ] structure form.<ref name = "Greenwood"/> In contrast, other group 2 oxides, ], ], ], ], crystallize in the cubic rock salt motif.<ref name = "Greenwood"/> At high temperature the structure transforms to a tetragonal form.<ref>{{cite book|author=A.F. Wells|year=1984|title=Structural Inorganic Chemistry|edition=5|publisher=Oxford Science Publications|isbn=0-19-855370-6}}</ref> In the vapor phase, beryllium oxide is present as discrete diatomic covalent molecules. The electronic structure of the beryllium oxide monomer is unusual, the orbital overlap only allows for one strong covalent bond to form, the other two orbitals do not overlap strongly enough to form a covalent bond, neither does it form an ionic bond. The result is a triplet diradical species, this is commonly simplified to a double bond.		BeO crystallizes in the hexagonal ] structure, featuring tetrahedral Be<sup>2+</sup> and O<sup>2−</sup> centres, like ] and w-] (with both of which it is ]). In contrast, the oxides of the larger group-2 metals, i.e., ], ], ], ], crystallize in the cubic ] with octahedral geometry about the dications and dianions.<ref name = "Greenwood"/> At high temperature the structure transforms to a tetragonal form.<ref>{{cite book |author=Wells, A. F. |year=1984 |title=Structural Inorganic Chemistry |edition=5 |publisher=Oxford Science Publications |isbn=0-19-855370-6}}</ref>
			In the vapour phase, beryllium oxide is present as discrete ]s. In the language of ], these molecules can be described as adopting ''sp'' ] on both atoms, featuring one ] (between one ''sp'' orbital on each atom) and one ] (between aligned ''p'' orbitals on each atom oriented perpendicular to the molecular axis). ] provides a slightly different picture with no ''net'' σ bonding (because the 2''s'' orbitals of the two atoms combine to form a filled sigma bonding orbital and a filled sigma* anti-bonding orbital) and two π bonds formed between both pairs of ''p'' orbitals oriented perpendicular to the molecular axis. The sigma orbital formed by the ''p'' orbitals aligned along the molecular axis is unfilled. The corresponding ground state is ...(2sσ)<sup>2</sup>(2sσ*)<sup>2</sup>(2pπ)<sup>4</sup> (as in the isoelectronic ] molecule), where both bonds can be considered as ] from oxygen towards beryllium.<ref>{{cite book |title=Fundamentals of Spectroscopy |url=https://books.google.com/books?id=gfM9B3JshegC&pg=PA234 |access-date=29 November 2011 |publisher=Allied Publishers |isbn=978-81-7023-911-6 |pages=234}}</ref>
	==Applications==		==Applications==
			High-quality crystals may be grown ], or otherwise by the ]. For the most part, beryllium oxide is produced as a white amorphous powder, ] into larger shapes. Impurities, like carbon, can give rise to a variety of colours to the otherwise colourless host crystals.
	] beryllium oxide, which is very stable, has ] characteristics.<ref>Günter Petzow, Fritz Aldinger, Sigurd Jönsson, Peter Welge, Vera van Kampen, Thomas Mensing, Thomas Brüning"Beryllium and Beryllium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a04_011.pub2}}</ref> Beryllium oxide is used in rocket engines.
			] beryllium oxide is a very stable ].<ref>Petzow, Günter; Aldinger, Fritz; Jönsson, Sigurd; Welge, Peter; van Kampen, Vera; Mensing, Thomas; Brüning, Thomas (2005) "Beryllium and Beryllium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a04_011.pub2}}</ref> Beryllium oxide is used in rocket engines{{cn|date=September 2023}} and as a transparent ] on ] ]. Metal-coated beryllium oxide (BeO) plates are used in the control systems of aircraft drive devices.<ref>{{cite web |url=https://www.samaterials.com/content/what-are-the-ceramic-materials-with-high-thermal-conductivity.html |title=What Are the Ceramic Materials With High Thermal Conductivity? |last=Trento |first=Chin |date=Dec 27, 2023 |website=Stanford Advanced Materials |access-date=Sep 3, 2024}}</ref>
	Beryllium oxide is used in many high-performance semiconductor parts for applications such as radio equipment because it has good ] while also being a good electrical insulator. It is used as a filler in some thermal interface materials such as ].<ref name="apmag">{{cite journal | author=Greg Becker, Chris Lee, and Zuchen Lin | title=Thermal conductivity in advanced chips — Emerging generation of thermal greases offers advantages | journal=Advanced Packaging| year=2005 | pages=2–4 | url=http://www.apmag.com/ | accessdate=2008-03-04}}</ref> Some ]s have used beryllium oxide ceramic between the ] chip and the metal mounting base of the package in order to achieve a lower value of ] than for a similar construction made with ]. It is also used as a structural ] for high-performance microwave devices, ]s, ]s, and ]s.
			Beryllium oxide is used in many high-performance ] parts for applications such as radio equipment because it has good thermal conductivity while also being a good electrical insulator. It is used as a filler in some thermal interface materials such as ].<ref name="apmag">{{cite journal |author1=Greg Becker |author2=Chris Lee |author3=Zuchen Lin |title=Thermal conductivity in advanced chips — Emerging generation of thermal greases offers advantages |journal=Advanced Packaging |year=2005 |pages=2–4 |url=http://www.apmag.com/ |access-date=2008-03-04 |url-status=dead |archive-url=https://web.archive.org/web/20000621233638/http://www.apmag.com/ |archive-date=June 21, 2000 }}</ref> It is also employed in ] and spreaders that cool electronic devices, such as ], lasers, and power amplifiers.<ref>{{cite web |url=https://www.preciseceramic.com/products/beryllium-oxide-ceramic.html |title=Beryllia (BeO) |website=Advanced Ceramic Materials |access-date=Oct 18, 2024}}</ref> Some ]s have used beryllium oxide ceramic between the ] chip and the metal mounting base of the package to achieve a lower value of ] than a similar construction of ]. It is also used as a structural ] for high-performance microwave devices, ]s, ]s {{citation needed|date=September 2024}}, and ]s. BeO has been proposed as a ] for naval marine high-temperature ]s (MGCR), as well as ]'s ] ] for space applications.<ref name="KiloPower Reactor Materials Study">{{cite web| last1=McClure |first1=Patrick |last2=Poston |first2=David |last3=Gibson |first3=Marc |last4=Bowman |first4=Cheryl |last5=Creasy |first5=John |title=KiloPower Space Reactor Concept – Reactor Materials Study |date=14 May 2014 |url=http://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-14-23402 |access-date=21 November 2017}}</ref>
	==Safety==		==Safety==
	Like all beryllium compounds, BeO is ]ic and may cause chronic ]. Once fired into solid form, it is safe to handle as long as it is not subjected to any machining that generates dust.<ref></ref> Beryllium oxide ceramic is not a hazardous waste under Federal law in the USA.		BeO is ]ic in powdered form<ref>{{cite web|url=https://nj.gov/health/eoh/rtkweb/documents/fs/0226.pdf|title=Hazardous Substance Fact Sheet|publisher=New Jersey Department of Health and Senior Services|access-date=August 17, 2018}}</ref> and may cause a chronic allergic-type lung disease ]. Once fired into solid form, it is safe to handle if not subjected to machining that generates dust. Clean breakage releases little dust, but crushing or grinding actions can pose a risk.<ref>{{cite web |url=https://www.americanberyllia.com/safety |title=Beryllium Oxide Safety |website=American Beryllia |access-date=2018-03-29}}</ref>
	==References==		==References==
	{{reflist|2}}		{{Reflist|30em}}
			==Cited sources==
			*{{cite book |ref=Haynes| editor= Haynes, William M. | date = 2016| title = ] | edition = 97th | publisher = ] | isbn = 9781498754293}}
	==External links==		==External links==
	*		*
			*
	*
	*
	*		*
	*		*
	*		*
	{{Beryllium compounds}}		{{Beryllium compounds}}
			{{Oxides}}
			{{oxygen compounds}}
			{{Authority control}}
	{{DEFAULTSORT:Beryllium Oxide}}		{{DEFAULTSORT:Beryllium Oxide}}
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