KBr (Potassium Bromide)
Potassium bromide (KBr) is
one of the most popular
materials used in
spectroscopy due to the wide
transmission range. It
corresponds to salt crystals
as well as KCl and NaCl.
KBr is a monocrystal, soft
and stable to thermal
influence however should be avoided from a contact with
water and spirit solutions, glycerin, and acids. Due to material
hygroscopicity the polished parts require storage in
desiccator or in sealed package with silica gel in a warm
Application
• IR/FTIR spectroscopy
Product types
• Plane-parallel windows and wedges
• Beamsplitter substrates for FTIR spectroscopy
• Lenses
Specifications
Tab.1. Typical specification of KBr optical components
Specification
Sizes
Typical
See table in the article
Plane Windows and
Wedged Windows
Diameter tolerance, mm +0/-0.25
Thickness tolerance, mm +/-0.25
Thickness matching, mm Surface quality, scr/dig 60/40
Surface flatness, λ @ 633 2
nm per inch*
Parallelism (wedge
5 arc min
tolerance)
Coating
none
Packaging
Typak®
State-of-the-art
RFQ
(up to 100mm size)
RFQ
RFQ
RFQ
RFQ
RFQ
Tab.2. Refractive index
λ, µm
0.391
0.405
0.486
0.589
0.811
1.701
8.662
11.862
17.400
18.160
21.180
21.830
23.860
25.140
n
1.594
1.590
1.572
1.560
1.547
1.539
1.529
1.522
1.504
1.501
1.487
1.483
1.471
1.463
Tab.3. Optical properties
Transmission range, microns
Color
Reflection losses (2
5µm
surfaces), %
11µm
Absorption coefficient, 10.6µm
cm-1
19µm
26µm
30µm
Restrahlen peak, µm
dN/dT, 10-6/C
dN/dµ = 0, µm
Birefringence, nm/cm
RFQ
Tab.4. Physical and mechanical properties
RFQ
Class/Structure
Transmission Spectrum
2
Density @300K, g/cm
Molecular Weight
Lattice constant, Ā
Melting Point, C
Thermal Conductivity @319K, W/(m x K)
Thermal Expansion @300K, 10-6/C
Hardness, Knoop with
in (100)
200g indenter
in (110)
Specific Heat Capacity, J/(kg x K)
Debye temperature, K
Dielectric Constant for @ 295K
102 - 1010 Hz
@ 360K
Bandgap, eV
Young Modulus (E), GPa
Shear Modulus (G), GPa
Bulk Modulus (K), GPa
Elastic Coefficient
Apparent Elastic Limit, MPa
Poisson Ratio
For the optics we use KBr material with absorption less than
0.5% in absorption bands (through reference 3mm thickness).
TYDEX
J.S.Co.
0.22 – 28 µm
colorless
8.8
8.3
≤ 0.001
≤ 0.05
≤ 0.33
≤ 0.7
77.6
- 40.83
4.2
<30
Домостроительная ул. 16, 194292 С.-Петербург, РОССИЯ
Тел : 7-812- 331870 1, - 3346701 ; Факс : 7-812- 3 092958
E-mail: [email protected], URL: http://www.tydex.ru
Cubic FCC, NaCl type,
Fm3m, (100) cleavage
2.753
119.01
6.60
730
4.816
43
7
5.9
435
174
4.90
4.97
7.6
64.79
5.08
15.02
C11 = 34.5 C12 = 5.4 C44
= 5.08
1.1 (160psi)
0.203
Tab.5. Chemical stability / Solubility
53.48 g/100cm3,
in water
о
(at 0 С)
hygroscopic
in acids
in organic solvents
glycerin
lower spirits
ether
soluble
soluble
soluble
insignificantly soluble
Please pay your attention that this article is for your
information only. We do not supply KBr in ingots as well as
semi-finished products. Our standard products are polished
parts.
For further information on our KBr optical components
please see the following: Windows for IR-spectroscopy, FTIR
beamsplitter substrates, Packaging or fill in our request form.
TYDEX
J.S.Co.
Домостроительная ул. 16, 194292 С.-Петербург, РОССИЯ
Тел : 7-812- 331870 1, - 3346701 ; Факс : 7-812- 3 092958
E-mail: [email protected], URL: http://www.tydex.ru