Lanthanum hexaboride

Lanthanum hexaboride
Names
	Other names Lanthanum boride
Identifiers
CAS Number	12008-21-8 ;
ChemSpider	21241507 ;
ECHA InfoCard	100.031.379
EC Number	234-531-6;
PubChem CID	71308229;
CompTox Dashboard (EPA)	DTXSID601010268 ;
	InChI InChI=1S/B6.La/c1-2-5(1)3-4(5)6(1,2)3;/q-2;+2 Key: VJXOKIULCJPJLW-UHFFFAOYSA-N ;
Properties
Chemical formula	LaB6
Molar mass	203.78 g/mol
Appearance	intense purple violet
Density	4.72 g/cm3
Melting point	2,210 °C (4,010 °F; 2,480 K)
Solubility in water	insoluble
Structure
Crystal structure	Cubic
Space group	Pm3m ; Oh
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Lanthanum hexaboride (La B₆, also called lanthanum boride and LaB) is an inorganic chemical, a boride of lanthanum. It is a refractory ceramic material that has a melting point of 2210 °C, and is insoluble in water and hydrochloric acid.^[1] It is extremely hard, with a Mohs hardness of 9.5.^[2] It has a low work function and one of the highest electron emissivities known, and is stable in vacuum. Stoichiometric samples are colored intense purple-violet, while boron-rich ones (above LaB_6.07) are blue. Ion bombardment changes its color from purple to emerald green.^[3] LaB₆ is a superconductor with a relatively low transition temperature of 0.45 K.^[4]

^ Trento, Chin (Jan 31, 2024). "An Introduction to Lanthanum Hexaboride". ACM. Retrieved Sep 3, 2024.
^ Schmidt, Kevin (2014). Computational Modeling of Lanthanum Hexaboride Materials: Interatomic Potentials and Molecular Dynamics (PDF) (Master of Science). University of Nevada, Reno. Retrieved 15 April 2022. Lanthanum hexaboride has a hardness of ≈ 9.5, similar to B4C and between corundum (Al2O3) and diamond on the low and high ends of the Mohs scale, respectively.
^ T. Lundström (1985). "Structure, defects and properties of some refractory borides" (PDF). Pure and Applied Chemistry. 57 (10): 1383–1390. doi:10.1351/pac198557101383. S2CID 93184983.
^ G. Schell; H. Winter; H. Rietschel; F. Gompf (1982). "Electronic structure and superconductivity in metal hexaborides". Phys. Rev. B. 25 (3): 1589–1599. Bibcode:1982PhRvB..25.1589S. doi:10.1103/PhysRevB.25.1589.

[1] Trento, Chin (Jan 31, 2024). "An Introduction to Lanthanum Hexaboride". ACM. Retrieved Sep 3, 2024.

[2] Schmidt, Kevin (2014). Computational Modeling of Lanthanum Hexaboride Materials: Interatomic Potentials and Molecular Dynamics (PDF) (Master of Science). University of Nevada, Reno. Retrieved 15 April 2022. Lanthanum hexaboride has a hardness of ≈ 9.5, similar to B4C and between corundum (Al2O3) and diamond on the low and high ends of the Mohs scale, respectively.

[3] T. Lundström (1985). "Structure, defects and properties of some refractory borides" (PDF). Pure and Applied Chemistry. 57 (10): 1383–1390. doi:10.1351/pac198557101383. S2CID 93184983.

[4] G. Schell; H. Winter; H. Rietschel; F. Gompf (1982). "Electronic structure and superconductivity in metal hexaborides". Phys. Rev. B. 25 (3): 1589–1599. Bibcode:1982PhRvB..25.1589S. doi:10.1103/PhysRevB.25.1589.

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