Potassium Chloride, Potassium Chloride transmission, Potassium Chloride properties, KCl

Potassium Chloride is used for infrared windows, lenses and prisms when transmission in the 0.3 µm - 20 µm range is desired. Potassium Chloride is soluble in water and polished surfaces must be protected from exposure to moisture. Maximum operating temperature is 400 °C. Maximum available size: 400 mm Dia x 50 mm Thk.

Chemical Formula	KCl
Crystal Class	Cubic
Lattice Constant, Å	6.29
Molecular Weight	74.55
Density, g/cm³ (20 °C)	1.98
Reflection Loss, % for two surfaces at 10 µm	6.8
Dielectric Constant for 10⁶ Hz at 302 K	4.64
Melting Temperature, K	1050
Thermal Conductivity, W/(m K) at 315 K	6.7
Thermal Expansion, 1/K at 300 K	36.6 x 10^-6
Specific Heat, cal/(g K) at 273 K	0.162
Debye Temperature, K	235
Bandgap, eV	8.5
Solubility, g/100 g H₂O at 293 K	34.7
Knoop Hardness, kg/mm²	7.2[110], 9.3[100]
Young's Modulus, GPa	29.63
Rupture Modulus, GPa	0.0044
Shear Modulus, GPa	6.24
Bulk Modulus, GPa	17.36

Wavelength, µm	0.40	0.59	5.30	11.7	15.0	18.1	20.2	22.8	24.3
Refractive Index	1.51	1.49	1.47	1.45	1.43	1.41	1.39	1.37	1.35