Material Lithium Fluoride (LiF)

Lithium Fluoride is used for windows, prisms, and lenses in the UV, visible and infrared where desired transmission is in the 0.104 µm - 7 µm range.

Modest precautions should be taken against moisture and high energy radiation damage. LiF is attacked by atmospheric moisture at 400 °C and softens at 600 °C. LiF is sensitive to thermal shock. Irradiation produces color centers. The material can be cleaved. Lithium fluoride is grown by vacuum Stockbarger technique in diameters of 115 mm. Although the optical characteristics are good the structure is not perfect and cleavage is difficult. For good structure LiF is less commonly grown by the Kyropoulos method (air-grown) specifically for monochromator plates. Cleavage is (100) and less commonly (110). LiF is slightly plastic and can be bent into radius plates.

Crystaltechno Ltd. manufactures from Lithium Fluoride (LiF) the following optics: windows, prisms, polished domes and lenses.
Maximum diameter of LiF optics - up to 250 mm, thickness 40 mm.


  Transmission Range   0.12 to 8.5 microns  
  Refractive Index   1.3943 at 0. 5 microns  
  Reflection Loss   5.4% at 0.5 µm (2 surfaces)  
  dn/dT   -12.7 x 10-6/ °C at 0.6 microns  
  Density   2.63905 g/cm3  
  Melting Point   870 °C  
  Thermal Conductivity   4. 01 W/(m K) at 41 °C  
  Thermal Expansion   37 x 10-6/ °C  
  Hardness   Knoop 102 to 113 kg/mm2 with 600g indenter  
  Specific Heat Capacity   1562 J/(kg K) at 10 °C  
  Dielectric Constant   9.1 at 25 °C  
  Young's Modulus (E)   64.79 GPa  
  Shear Modulus (G)   55.14 GPa  
  Bulk Modulus (K)   62.03 GPa  
  Elastic Coefficients   C11=97.4 C12=40.4 C44=55.4  
  Apparent Elastic Limit   11.2 MPa  
  Poisson Ratio   0.326  
  Solubility   0.27g/l00g water at 20 °C  
  Molecular Weight   25.94  
  Class/Structure   FCC, NaCl structure. Cleavage (100)    


  Wavelength, µm 0.20 0.22 0.24 0.29 0.39  
  Refractive Index 1.44 1.43 1.42 1.41 1.40  
  Wavelength, µm 0.60 1.75 2.75 3.40    
  Refractive Index 1.39 1.38 1.37 1.36    

Plano-Convex Lenses
Bi-Convex Lenses
Bi-Concave Lenses
Right Angle Prisms
Dispersion prisms
Polished Domes

Ordering Info
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+7 (495) 234-5951, 234-5952, 956-7610
fax +7 (495) 433-1551
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