Almaz Optics, Inc.
12 Chadsford Ct.  Marlton, NJ 08053, USA
Tel:  856 797-0491, Fax: 856 797-0228
e-mail: mail@almazoptics.com

 

POTASSIUM BROMIDE, KBr

Potassium Bromide is used for windows and prisms when transmission through the 0.25 µm - 26 µm range is desired. Potassium Bromide is water soluble and must be protected against moisture degradation of polished surfaces. The material cleaves readily, and can be used at temperatures up to 300 °C. Irradiation of Potassium Bromide produces color centers. Maximum available size: 140 mm Dia x 50 mm Thk.

Main Properties

Chemical Formula

KBr
Molecular Weight 119.01

Crystal Class

Cubic

Lattice Constant, Å

6.60

Density, g/cm3 at 300 K

2.75

Absorption Coefficient, 1/cm
at 2.7 µm
at 3.8 µm
1.2 x 10-4
1.6 x 10-4
Reflection Loss for two surfaces at 10 µm, % 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
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

Refractive Index

Wavelength, µm

0.39

0.44

0.49

0.59

0.80

1.50

8.50

12.0

17.0

18.1

20.5

22.0

23.9

25.2

Refractive Index

1.59

1.58

1.57

1.56

1.55

1.54

1.53

1.52

1.51

1.50

1.49

1.48

1.47

1.46

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