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KRS5 Thallium Bromo-Iodide
KRS5 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.
Products
Windows
Prisms & ATR
| 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 |
| 1.30 | 2.42066 |
| 2.00 | 2.38974 |
| 3.00 | 2.38594 |
| 4.00 | 2.38204 |
| 5.00 | 2.37977 |
| 6.00 | 2.37797 |
| 7.00 | 2.37652 |
| 8.00 | 2.37452 |
| 9.00 | 2.37267 |
| 10.00 | 2.36854 |
| 11.00 | 2.36684 |
| 12.00 | 2.36531 |
| 13.00 | 2.36371 |
| 14.00 | 2.36101 |
| 15.00 | 2.35810 |
| 16.00 | 2.35610 |
| 17.00 | 2.35372 |
| 18.00 | 2.35137 |
| 19.00 | 2.34451 |
| 20.00 | 2.34085 |
| 21.00 | 2.33650 |
| 22.00 | 2.33240 |
| 23.00 | 2.32860 |
| 24.00 | 2.32490 |
| 25.00 | 2.31729 |
| 26.00 | 2.31295 |
| 27.00 | 2.30698 |
| 28.00 | 2.30098 |
| 29.00 | 2.29495 |
| 30.00 | 2.28867 |
| 31.00 | 2.28212 |
| 32.00 | 2.27531 |
| 33.00 | 2.26827 |
| 34.00 | 2.26087 |
| 35.00 | 2.25322 |
| 36.00 | 2.24528 |
| 37.00 | 2.23705 |
| 38.00 | 2.22850 |
| 39.00 | 2.21965 |
| 40.00 | 2.21050 |
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
