World Library  
Flag as Inappropriate
Email this Article

Lithium fluoride

Article Id: WHEBN0002687105
Reproduction Date:

Title: Lithium fluoride  
Author: World Heritage Encyclopedia
Language: English
Subject: Lithium, Dictionary of chemical formulas, Thermoluminescent dosimeter, Lithium iodide, Lithium bromide
Collection: Alkali Metal Fluorides, Crystals, Fluorides, Lithium Compounds, Metal Halides, Optical Materials
Publisher: World Heritage Encyclopedia

Lithium fluoride

Lithium fluoride
Lithium fluoride boule
Lithium fluoride
IUPAC name
Lithium fluoride
ChemSpider  Y
EC number 232-152-0
Jmol-3D images Image
RTECS number OJ6125000
Molar mass 25.939(2) g/mol
Appearance white powder or transparent crystals,
Density 2.635 g/cm3
Melting point 845 °C (1,553 °F; 1,118 K)
Boiling point 1,676 °C (3,049 °F; 1,949 K)
0.27 g/100 mL (18 °C)[1]
0.134 g/100 mL (25 °C)
Solubility soluble in HF
insoluble in alcohol
a = 403.51 pm
1.604 J/(g K)
1.376 J/(g K)
-616 kJ/mol
NFPA 704
Lethal dose or concentration (LD, LC):
LD50 (Median dose)
143 mg/kg (oral, rat)[2]
Related compounds
Other anions
Lithium chloride
Lithium bromide
Lithium iodide
Other cations
Sodium fluoride
Potassium fluoride
Rubidium fluoride
Caesium fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 Y  (: Y/N?)

Lithium fluoride is an chemical formula LiF. It is a colorless solid, that transitions to white with decreasing crystal size. Although odorless, lithium fluoride has a bitter-saline taste. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. It is mainly used as a component of molten salts.[3] Formation of LiF releases one of the highest energy per mass of reactants, only second to that of BeO.


  • Manufacturing 1
  • Applications 2
    • In molten salts 2.1
    • Optics 2.2
    • Radiation detectors 2.3
    • Nuclear reactors 2.4
    • Cathode for PLED and OLEDs 2.5
  • References 3


LiF is prepared from lithium hydroxide and hydrogen fluoride or by dissolving lithium carbonate in excess hydrogen fluoride, evaporating to dryness and heating to red hot.


In molten salts

Fluorine is produced by the electrolysis of molten potassium bifluoride. This electrolysis proceeds more efficiently when the electrolyte contains a few percent of LiF, possibly because it facilitates formation of Li-C-F interface on the carbon electrodes.[3] A useful molten salt, FLiNaK, consists of a mixture of LiF, together with sodium fluoride and potassium fluoride. The primary coolant for the Molten-Salt Reactor Experiment was FLiBe; LiF-BeF2 (66-33 mol%).


Because of its large band gap, LiF crystals are transparent to short wavelength ultraviolet radiation, more so than any other material. LiF is therefore used in specialized UV optics,[4] (See also magnesium fluoride). Lithium fluoride is used also as crystal in X-ray spectrometry.

Radiation detectors

It is also used as a means to record ionizing radiation exposure from gamma rays, beta particles, and neutrons (indirectly, using the 6
(n,alpha) nuclear reaction) in thermoluminescent dosimeters.

Nuclear reactors

Lithium fluoride (highly enriched in the common isotope lithium-7) forms the basic constituent of the preferred fluoride salt mixture used in liquid-fluoride nuclear reactors. Typically lithium fluoride is mixed with beryllium fluoride to form a base solvent (FLiBe), into which fluorides of uranium and thorium are introduced. Lithium fluoride is exceptionally chemically stable and LiF/BeF2 mixtures (FLiBe) have low melting points (360 C - 459 C) and the best neutronic properties of fluoride salt combinations appropriate for reactor use. MSRE used two different mixtures in the two cooling circuits.

Cathode for PLED and OLEDs

Lithium fluoride is widely used in PLED and OLED as a coupling layer to enhance electron injection. The thickness of LiF layer is usually around 1 nm. The dielectric constant (or relative permittivity) of LiF is 9.0[5]


  1. ^ "Lithium fluoride". Retrieved 2006-02-26. 
  2. ^
  3. ^ a b J. Aigueperse, P. Mollard, D. Devilliers, M. Chemla, R. Faron, R. Romano, J. P. Cuer, "Fluorine Compounds, Inorganic" in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a11_307.
  4. ^ "Crystran Ltd., a manufacturer of infrared and ultraviolet optics". Retrieved 2010-12-28. 
  5. ^ C. Andeen, J. Fontanella,D. Schuel, "Low-Frequency Dielectric Constant of LiF, NaF, NaC1, NaBr, KC1, and KBr by the Method of Substitution", Physical Review B, 2, 5068-5073 (1970) doi:10.1103/PhysRevB.2.5068.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.