KRS5 Thallium Bromo-Iodide
DownloadKRS5 deep IR material with a high refractive index, KRS5 is used extensively in spectroscopy for ATR prisms, windows and lenses. In conjunction with Germanium, KRS5 can also be used in athermalised IR imaging systems.
Transmission Range
0.6 to 40 μm
Refractive Index
2.371 at 10 μm (1)(3)
Reflection Loss
28.4% at 10 μm (2 surfaces)
Absorption Coefficient
n/a
Reststrahlen Peak
n/a
dn/dT
-235 x 10-6 /°C
dn/dμ = 0
7 μm
Density
7.371 g/cc (3)
Melting Point
414.5°C (3)
Thermal Conductivity
0.544 W m-1 K-1 @ 293 K
Thermal Expansion
58 x 10-6/°C (2)
Hardness
Knoop 40.2 (2)
Specific Heat Capacity
200 J Kg-1 K-1 at 273K
Dielectric Constant
32.5
Youngs Modulus (E)
15.85 GPa (2)
Shear Modulus (G)
5.79 GPa (2)
Bulk Modulus (K)
19.78 GPa (2)
Elastic Coefficients
C11=331; C12=13.2; C44=5.79
Apparent Elastic Limit
26.2 MPa (2)
Poisson Ratio
0.369
Solubility
0.05g/100g water at 293K
Molecular Weight
42 mole% TlBr; 58 mole% TlI
Class/Structure :
Cubic, CsCl structure, Pm3m, No cleavage (3)
| µm | No |
|---|---|
| 0.54 | 2.68059 |
| 1.00 | 2.44620 |
| 1.50 | 2.40774 |
| 2.00 | 2.39498 |
| 3.00 | 2.38574 |
| 4.00 | 2.38204 |
| 5.00 | 2.37979 |
| 6.00 | 2.37797 |
| 7.00 | 2.37627 |
| 8.00 | 2.37452 |
| 9.00 | 2.37267 |
| 10.0 | 2.37069 |
| 11.0 | 2.36854 |
| 12.0 | 2.36622 |
| 13.0 | 2.36371 |
| µm | No |
|---|---|
| 14.0 | 2.36101 |
| 15.0 | 2.3581 |
| 16.0 | 3.35502 |
| 17.0 | 2.35173 |
| 18.0 | 2.34822 |
| 19.0 | 2.34451 |
| 20.0 | 2.34058 |
| 21.0 | 2.33643 |
| 22.0 | 2.33206 |
| 23.0 | 2.32746 |
| 24.0 | 2.32264 |
| 25.0 | 2.31758 |
| 26.0 | 2.31229 |
| 27.0 | 2.30676 |
| 28.0 | 2.30098 |
| µm | No |
|---|---|
| 29.0 | 2.29495 |
| 30.0 | 2.28867 |
| 31.0 | 2.28212 |
| 32.0 | 2.27531 |
| 33.0 | 2.26823 |
| 34.0 | 2.26087 |
| 35.0 | 2.25322 |
| 36.0 | 2.24528 |
| 37.0 | 2.23705 |
| 38.0 | 2.22850 |
| 39.0 | 2.21965 |
| 40.0 | 2.21047 |
KRS-5 crystalises by the sealed-ampoule Stockbarger technique. Starting materials of the highest purity are selected to ensure that there are no anionic absorption bands between 2μm and 16μm and all crystals are checked for quality by using a pathlength of 120mm.
CAUTION: Thallium salts are considered TOXIC and should be handled with care.
REFERENCES
(1) Rodney and Malitson J.Opt Soc.Am. V46, p 956, 1953
(2) Combes, Ballard, McCarthy: J.Opt Soc.Am. V41, p 215, 1951
(3) Handbook of Optical Constants, ed Palik, V3, ISBN 0-12-544423-0
