23 May 2025 LiF(lithium fluoride crystal) is an optical infrared crystal which transmits from 0.10 to 7µm.
OPTICAL
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)
Restrahlen Peak 25 microns
dN/dT -12.7 x 10-6/ °C at 0.6 microns
PHYSICAL
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
CHEMICAL
Solubility 0.27g/l00g water at 20 °C
Molecular Weight 25.94
Class/Structure FCC, NaCl structure. Cleavage (100) | 
