LiF crystal shows excellent transmittance in the VUV region.
It is used for optical windows, prisms, and lenses in the
visible and infrared in 0.104 ¦Ìm - 7 ¦Ìm. LiF crystal is sensitive
to thermal shock and would be attacked by atmospheric moisture
at 400¡ãC. In addition irradiation produces color centers.
Modest precautions should be taken against moisture and high
energy radiation damage. Besides LiF softens at 600¡ãC and
is slightly plastic that can be bent into radius plates. The
material can be cleaved along (100) and less commonly (110).
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 technique (air-grown)
specifically for monochromator plates. High quality LiF is
usually grown by modified Bridgman technique. Maximum available
size in diameters is about 115mm. LiF is slightly plastic
and can be bent into radius plates.
