Potassium chloride
Material
KCl
Kaliumchlorid (KCl) has high transmission in the wavelength range between 0.3 µm and 20 µm. The material has a low refractive index and a high optical damage threshold. Potassium chloride is hygroscopic and highly soluble in water, so it must be stored in a dry environment or protected against moisture by means of a protective coating. Thermally, the use of KCl is limited to 400 °C.
Optics made of KCl are used in IR spectroscopy and as protective windows for CO2 lasers.2 lasers.
Properties
Optical and spectral properties | |
---|---|
Transmission range in µm (minimum 10%) | 0,18‐25,1 |
Transmission range in µm (minimum 50%) | 0,18‐25,0 |
Refractive index @633nm | 1,488 (1,456 @10µm) |
Reflection losses in % at 1 surface | 3,45 @10µm
|
Reflection losses, % for two surfaces | 6,7 @10,6µm
|
dN/dT in 1/K | -33,2 · 10-6
|
Physical properties | |
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Density in g/cm3 | 19,989
|
Melting point in °C | 776 |
Specific heat capacity in J/(kg · K) | 693
|
Thermal conductivity in W/(m · K) | 6,53
|
Thermal expansion in 1/K | 36 · 10-6
|
Dielectric constant | 4,64
|
Solubility in water in g/100g | 34,7 @25°C |
Mohs hardness | 2
|
Knoop hardness in kg/mm² | 9,3 (<100>)
|
Material type | single crystalline, synthetic
|
Crystal type | cubic, face-centered |
Crystal structure | Fm3m
|
Lattice constant in Å | a = 6,29
|
Elastic coefficient in GPa | C11 = 40,5 C12 = 6,9 C44 = 6,27 |
Young's Modulus (E) in Gpa | 29,63
|
Shear Modulus (G) in GPa | 6,24 |
Bulk Modulus (K) in GPa | 17,36 |
Rupture Modulus in MPa | 4,4 |
Apparent elastic limit in MPa | 4,4
|
Poisson's ratio | 0,29 |
Spectral properties |
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sample thickness: 2 mm |
Optical Properties | |
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Transmission range in µm @10% min. | 0.18 - 25.1 |
Transmission range in µm @50% min. | 0.18 - 25.0 |
Refractive index @ 633nm | 1.488099 (1.45644 @10µm) |
Reflection losses in % at 1 surface | 3.45 @ 10µm |
Reflection losses in % at 2 surfaces | 6.7 @ 10.6µm |
dn/dT in 1/K | -33.2 · 10-6 |
Physical Properties | |
---|---|
Density in g/cm³ | 1.989 |
Melting point in °C | 776 |
Specific heat capacity in J/(kg · K) | 6936 |
Thermal Conductivity in W/(m · K) | 6.53 |
Thermal Expansion in 1/K | 36 · 10-6 |
Dielectric constant | 4.64 |
Solubility in water in g/100g | 34.7 @ 20°C |
Mohs hardness | 2 |
Knoop hardness in kg/mm² | 18,2 (<100>) |
Material type | Single crystal, synthetic |
Crystal type | cubic face-centered |
Crystal structure | Fm3m |
Lattice constant in Å | a = 6.29 |
Elastic coeficients in GPa | C11 = 40.5 C12 = 6.9 C44 = 6.27 |
Young's Modulus (E) in GPa | 29.63 |
Shear Modulus (G) in GPa | 6.24 |
Bulk Modulus (K) in GPa | 17.36 |
Rupture Modulus in MPa | 4.4 |
Apparent elastic limit in MPa | 4.4 |
Poisson ratio | 0.29 |
Spectral Properties | |
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