Sodium chloride

Material
NaCl

Natriumchlorid (NaCl) is a material with high transmission in the wavelength range between 0.25 µm and 16 µm and is therefore used for optical windows, lenses and prisms for the UV and IR range. Due to its low absorption, sodium chloride is mainly used in high-power laser systems.

Sodium chloride is hygroscopic and highly soluble in water. Therefore, its use requires a dry environment or a special protective layer against moisture. Sodium chloride can be used at temperatures up to over 400 °C, but is sensitive to thermal shock.

Properties
Optical and spectral properties
Transmission range in µm (minimum 10%)
0,17‐23
Transmission range in µm (minimum 50%)
0,18‐20
Refractive index @633nm
1,542

(1,490 @10,6µm)

Reflection losses in % at 1 surface
3,93 @10µm
Reflection losses, % for two surfaces
7,6 @10,6µm
dN/dT in 1/K
-36 · 10-6
Physical properties
Density in g/cm3
2,164
Melting point in °C
801
Specific heat capacity in J/(kg · K)
870
Thermal conductivity in W/(m · K)
6,49
Thermal expansion in 1/K
44 · 10-6
Dielectric constant
5,9
Solubility in water in g/100g
36 @25°C
Mohs hardness
3
Knoop hardness in kg/mm²
18,2
Material type
single crystalline, synthetic
Crystal type
cubic, face-centered
Crystal structure
cF8
Lattice constant in Å
a = 5,56
Elastic coefficient in GPa
C11 = 49,1

C12 = 12,8

C44 = 12,8

Young's Modulus (E) in Gpa
39,98
Shear Modulus (G) in GPa
12,61
Bulk Modulus (K) in GPa
24,42
Rupture Modulus in MPa
2,4
Apparent elastic limit in MPa
3,9
Poisson's ratio
0,26
Spectral properties
sample thickness: 2 mm
Optical Properties
Transmission range in µm @10% min. 0.17 - 23
Transmission range in µm @50% min. 0.18 - 20
Refractive index @ 633nm 1.54159
(1.49065 @10.6µm)
Reflection losses in % at 1 surface 3.93 @ 10µm
Reflection losses in % at 2 surfaces 7.6 @ 10.6µm
dn/dT in 1/K -36 · 10-6
Physical Properties
Density in g/cm³ 2.164
Melting point in °C 801
Specific heat capacity in J/(kg · K) 870
Thermal Conductivity in W/(m · K) 6.49
Thermal Expansion in 1/K 44 · 10-6
Dielectric constant 5.9
Solubility in water in g/100g 36 @ 25°C
Mohs hardness 3
Knoop hardness in kg/mm² 18.2 (<100>)
Material type Single crystal, synthetic
Crystal type cubic face-centered
Crystal structure cF8
Lattice constant in Å a = 5.6
Elastic coeficients in GPa C11 = 49.1
C12 = 12.8
C44 = 12.8
Young's Modulus (E) in GPa 39.98
Shear Modulus (G) in GPa 12.61
Bulk Modulus (K) in GPa 24.42
Rupture Modulus in MPa 2.4
Apparent elastic limit in MPa 3.9
Poisson ratio 0.26
Spectral Properties