KCl (Potassium Chloride)

Download KCl (Potassium Chloride) Datasheet (PDF, 468 KB)

KBrPotassium chloride (KCl) is used in IR spectroscopy as well as in high power CO2 laser applications. It refers to salt crystals (like KBr and NaCl). KCl is a soft and stable to thermal influence monocrystal. Due to material hygroscopicity the polished parts require storage in desiccator or in sealed package with silica gel in a warm room.

Application:

  • IR spectroscopy
  • CO2 laser optics

Product types:

  • Plane-parallel windows and wedges
  • Lenses

Specifications

Tab.1. Typical specification of KCl optical components

Specification Typical State-of-the-art
Sizes See table in the article Plane Windows and Wedged Windows Up to 100 mm
Diameter tolerance, mm +0/-0.25 RFQ
Thickness tolerance, mm ±0.25 RFQ
Thickness matching, mm RFQ
Surface quality, scr/dig 60/40 RFQ
Surface flatness, λ @ 633nm per inch* 2 RFQ
Parallelism (wedge tolerance) 5 arc min RFQ
Coating none protecting
Packaging Typak®  

Transmission Spectrum

KBr

The measurements were carried out on Perkin Elmer Lambda-35 spectrophotometer and on BrukerVertex-70 Fourier-spectrometer.

Tab.2. Refractive index

λ, µm n
0.20 1.7187
0.51 1.4962
1.18 1.4783
5.00 1.4705
6.00 1.4684
7.00 1.466
8.00 1.4629
9.00 1.4600
10.00 1.4564
11.00 1.4524
12.00 1.4480
13.00 1.4431
14.00 1.4378
15.00 1.4320
16.00 1.4256
17.00 1.4188
18.00 1.4113
19.00 1.4033
20.00 1.3947
21.00 1.3854
22.00 1.3754
23.00 1.3646
24.00 1.3530
25.00 1.3406
26.00 1.3272
27.00 1.3128
28.00 1.2973

Tab.3. Optical properties

Transmission range, microns 0.22-21
Colour Colourless
Reflection losses @ 11 µm (2 surfaces), % 8.3
Absorption coefficient, @ 3.8 µm, 10-4 cm-1 1.6
Restrahlen peak, μm 63.1
dN/dT, 10-6/C -33.2

Tab.4. Physical and mechanical properties

Class / Structure Cubic FCC, NaCl type, Fm3m, (100) cleavage
Density @300K, g/cm2 1.98
Molecular Weight 74.55
Melting Point, °C 776
Thermal Conductivity @322K, W/(mxK) 6.53
Thermal Expansion @300K, 10-6/C 36
Hardness, Knoop with 200g indenter in (100) 9.3
in (110) 7.2
Specific Heat Capacity, J/(kg×K) 690
Debye temperature, K 235
Dielectric Constant for 106 Hz @300K 4.64
Bandgap, eV 8.5
Young Modulus (E), GPa 29.67
Shear Modulus (G), GPa 6.24
Bulk Modulus (K), GPa 17.36
Elastic Coefficient C11 = 40.2 C12 = 6.7 C44 = 6.29
Apparent Elastic Limit, MPa 2.3 (330psi)
Poisson Ratio 0.216

Tab.5. Chemical stability / Solubility

in water
(at 0 оС)
34.7 g/100cm3
hygroscopic
in acids soluble
in organic solvents:  
spirits insignificantly soluble

Please pay your attention that this article is for your information only. We do not supply KCl in ingots as well as semi-finished products. Our standard products are polished parts.

For further information on our KCl optical components please see the following: Windows for IR-spectroscopy, Packaging or fill in our request form.
Optics Stock
Optics is ready to be shipped!
Stock is updated weekly.

Terms&Conditions of Sale
Shipment/ Payment/ Warranty ...
HRFZ-Si Axicones
A new product among TYDEX THz lenses!

An axicone is a specialized type of lens which has a conical surface. It is used to transform a Gaussian beam into a Bessel beam.