Фторид лития LiF

МакроОптика produces lenses, windows, prisms, wedges and others optical components according to customers’ specifications and drawings out of crystals lithium fluoride LiF.

Lithium fluoride is the material with the most extreme UV transmission of all and is used for special UV optics. Lithium fluoride transmits well into the VUV region at the hydrogen Lyman-alpha line (121nm) and beyond. Lithium fluoride is also used for X-ray monochromator plates where its lattice spacing makes it the most useful analysis crystal.

Lithium Fluoride is grown by vacuum Stockbarger technique in ingots approximately 100mm diameter. Lithium Fluoride cleaves easily and must be worked with extreme care. Polishing, particularly steep radii, often causes surface "rip-out".

Product Data

Transmission Range  0.12 to 6 Ојm
Refractive Index  1.392 at 0.6 Ојm (1)
Reflection Loss  5.2% at 0.6 Ојm (2 Surfaces)
Absorption Coefficient  5.9 x 10-3 cm-1 at 4.3 Ојm @ 300K (5)
Reststrahlen Peak  25 Ојm
dn/dT  -16 x 10-6 at 1.15 Ојm
dn/dОј 0 : 1.3 Ојm
Density  2.639 g/cc
Melting Point  848 В°C (6)
Thermal Conductivity  4.01 W m-1 K-1 at 314 K (2)
Thermal Expansion  37 x 10-6 K-1 at 283 K (2)
Hardness  Knoop 102 with 600g indenter (2)
Specific Heat Capacity  1562 J Kg-1 K-1
Dielectric Constant  0.1
Youngs Modulus (E)  64.97 GPa (2)
Shear Modulus (G)  55.14 GPa (2)
Bulk Modulus (K)  62.03 GPa (2)
Elastic Coefficients  C11=112; C12=46; C44=63.5 (3)
Apparent Elastic Limit  11.2 MPa (1620 psi) (4)
Poisson Ratio  0.326 (calculated)
Solubility  0.27g / 100g water at 20 В°C
Molecular Weight  25.94
Class/Structure  Cubic FCC, NaCl, Fm3m, (100) cleavage

Transmittance

Refractive Index

No = Ordinary Ray

µm No µm No µm No
0.106 1.9130 0.108 1.8330 0.110 1.7770
0.121 1.6240 0.130 1.5690 0.140 1.5300
0.150 1.5030 0.160 1.4840 0.170 1.4690
0.180 1.4850 0.190 1.4455 0.200 1.4391
0.220 1.4291 0.250 1.4189 0.260 1.4164
0.270 1.4141 0.280 1.4121 0.290 1.4103
0.300 1.4087 0.310 1.4073 0.320 1.4060
0.330 1.4048 0.340 1.4037 0.350 1.4028
0.360 1.4019 0.400 1.3989 0.500 1.3943
0.600 1.3918 0.700 1.3902 0.800 1.3890
0.900 1.3880 1.000 1.3871 1.500 1.3832
2.000 1.3788 2.500 1.37327 3.000 1.3666
3.500 1.3587 4.000 1.3494 4.500 1.3388
5.000 1.3266 5.100 1.3240 5.200 1.3213
5.300 1.3186 5.400 1.3158 5.500 1.3129
5.600 1.3099 5.700 1.3069 5.800 1.3038
5.900 1.3007 6.000 1.2975