Lithium fluoride

Lithium fluoride (LiF) is a highly versatile optical material with a range of beneficial properties that make it valuable for numerous applications in optics and photonics.

One of its primary attributes is its exceptional transparency in the ultraviolet (UV) spectrum, making it highly suitable for applications requiring UV transmission. LiF typically exhibits transparency from around 120nm to 10μm, although its transmission range can extend into the visible and infrared regions depending on its purity and crystalline structure.

LiF also possesses a relatively high refractive index, typically around 1.39 in the visible spectrum. This property makes it useful for fabricating optical components such as lenses, prisms, windows, where precise control over light propagation and refraction is essential.

In addition to its optical transparency and refractive properties, LiF is notable for its excellent mechanical and thermal stability. It is resistant to thermal shock and can withstand high temperatures without significant deformation or degradation, making it suitable for use in harsh environmental conditions.

LiF is commonly used in various optical applications, including spectroscopy, laser systems, UV lithography, and fluorescence microscopy. It is also employed as a material for optical coatings and filters due to its ability to transmit specific wavelengths of light while blocking others.

Despite its advantageous properties, LiF can be relatively expensive and sensitive to moisture and handling. Therefore, proper care and storage are essential to maintain its optical performance and longevity.

Overall, lithium fluoride (LiF) serves as a valuable optical material with a broad range of applications, particularly in UV optics, where its exceptional transparency and stability make it an indispensable choice for numerous optical systems and devices.

Lithium Fluoride (LiF) is an optical material with the following technical properties:

Transmission Range: 0.12 to 6 μm

Refractive Index: 1.392 at 0.6 μm

Reflection Loss: 5.2% at 0.6 μm (2 surfaces)

Absorption Coefficient: 5.9 x 10-3 cm-1 at 4.3 μm @ 300K

Reststrahlen Peak: 25 μm

dn/dT: -16 x 10-6 K-1 at 1.15 μm

Density: 2.639 g/cc

Melting Point: 848°C

Thermal Conductivity: 11.3 W m-1 K-1 at 314 K

Thermal Expansion: 37 x 10-6 K-1 at 283 K

Hardness Knoop: 102 with 600g indenter

Specific Heat Capacity: 1562 J Kg-1 K-1

Dielectric Constant: 0.1

Young’s Modulus (E): 64.97 GPa

Shear Modulus (G): 54.14 GPa

Bulk Modulus (K): 62.03 GPa

Elastic Coefficients: C11 = 112, C12 = 46, C44 = 63.5

Apparent Elastic Limit: 11.2 MPa (1620psi)

Poisson Ratio: 0.326 (calculated)

Solubility: 0.27g/100g water at 20°C

Molecular Weight: 25.94

Class/Structure: Cubic FCC, Fm3m (#221), NaCl structure, (100) cleavage

Please note that these values are typical and may vary based on the grade and manufacturing process of the material