Materials>>KBr

Potassium Bromide (KBr). KBr windows and beamsplitters

Alkor Technologies - manufacturer of KBr optical components. We supply KBr windows, Drilled KBr cells, KBr wedges, KBr beamsplitters and KBr blanks according to customer's specifications. Moisture protective coating (Parylene analog) can be applied on all KBr windows.

The largest diameter of KBr optics is 100mm. Please contact us for more information.

Please visit our KBr windows catalog. New!

KBr transmission. Sample thickness 10mm

KBr transmittance. Sample thickness 10mm.

Potassium Bromide is used for windows and prisms when transmission through the range 0.25µm to 26µm is desired. Potassium Bromide (KBr) is a material commonly used in FTIR spectroscopy.  Potassium Bromide is water soluble and KBr windows must be protected against moisture degradation of polished surfaces. Alkor provides special anti-moisture polymer coating - Parylene analog to protect KBr optics. KBr windows cleaves readily, and can be used at temperatures up to 300C. Irradiation of Potassium Bromide produces color centers.

Packing: All KBr optics carefully packaged into plastic boxes with silicagel and sealed with special moisture protective film.

KBr properties

Chemical Formula

KBr

Molecular Weight 119.01

Crystal Class

Cubic

Lattice Constant,

6.60

Density, g/cm3 at 300 K

2.75

Absorption Coefficient, 1/cm
at 2.7 m
at 3.8 m


1.2 x 10-4
1.6 x 10-4
Reflection Loss for two surfaces at 10 m, % 8.4
Dielectric Constant
for 102-1010 Hz at 298 K
for 102-1010 Hz at 360 K

4.9
4.97
Melting Temperature, K 1000
Thermal Conductivity, W/(m K) at 319 K 4.8
Thermal Expansion, 1/K at 300 K 38.5 x 10-6
Specific Heat, cal/(g K) at 273 K 0.104
Debye Temperature, K 174
Bandgap, eV 7.6
KBr Solubility, g/100 g H2O at 273 K 53.48

Knoop Hardness, kg/mm2

7.0 [100]

Young's Modulus, GPa 26.87
Rupture Modulus, GPa 0.0039
Shear Modulus, GPa 5.08
Bulk Modulus, GPa 15.02

KBr - Refractive Index

µm    No µm    No µm    No
0.405    1.5898 0.436    1.5815 0.486    1.5718
0.508    1.5684 0.546    1.5639 0.587    1.5600
0.643    1.5559 0.707    1.5524 1.014    1.5441
2.440    1.5373 3.419    1.5361 4.258    1.5352
6.238    1.5329 8.662    1.5290 9.724    1.5270
11.04    1.5240 14.29    1.5150 17.40    1.5039
19.91    1.4929 23.86    1.4714 25.14    1.4632
28.00    1.4423 30.00    1.4253