Potassium chloride

Material
KCl

Kaliumchlorid (KCl) hat eine hohe Transmission im Wellenlängenbereich zwischen 0,3 µm und 20 µm. Das Material besitzt einen geringen Brechungsindex und eine hohe optische Zerstörschwelle. Kaliumchlorid ist hygroskop und in Wasser stark löslich, daher muss es in trockener Umgebung gelagert oder mittels einer Schutzschicht gegen Feuchtigkeit abgesichert werden. Thermisch ist die Verwendung von KCl auf 400 °C begrenzt.

Optiken aus KCl finden Einsatz in der IR-Spektroskopie sowie als Schutzfenster für CO2 lasers.

Properties
Optical 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
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
sample thickness: 2 mm
Optical Properties
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