KRS6 Thallium Bromo-Chloride
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Transmission Range
0.4 to 25 μm
Refractive Index
2.1723 at 11 μm (1)
Reflection Loss
24% at 11 μm (2 surfaces)
Absorption Coefficient
n/a
Reststrahlen Peak
91.5 μm
dn/dT
n/a
dn/dμ = 0
5 μm
Density
7.18 g/cc (3)
Melting Point
423°C
Thermal Conductivity
0.7 W m-1 K-1 @ 329 K
Thermal Expansion
50 x 10-6 K-1 (2)
Hardness
Knoop 29.9 with 500g indenter (2)
Specific Heat Capacity
188 J Kg-1 K-1
Dielectric Constant
32 at 1 MHz
Youngs Modulus (E)
20.68 GPa (2)
Shear Modulus (G)
8.48 GPa (2)
Bulk Modulus (K)
22.81 GPa (2)
Elastic Coefficients
C11 = 38.5 C12 = 14.9 C44 = 7.37
Apparent Elastic Limit
20.7 MPa (3000psi)
Poisson Ratio
0.219
Solubility
0.3g/100g water at 20°C
Molecular Weight
40 mole% TlBr; 60 mole% TlCl
Class/Structure
Cubic, CsCl structure, Pm3m, no cleavage (3)
| µm | No |
|---|---|
| 0.6 | 2.3294 |
| 0.7 | 2.2982 |
| 0.8 | 2.2660 |
| 0.9 | 2.251 |
| 1.0 | 2.2404 |
| 1.5 | 2.2148 |
| 2.0 | 2.2059 |
| 3.0 | 2.199 |
| 4.0 | 2.1956 |
| 5.0 | 2.1928 |
| 6.0 | 2.190 |
| 7.0 | 2.187 |
| µm | No |
|---|---|
| 8.0 | 2.1839 |
| 9.0 | 2.1805 |
| 10.0 | 2.1767 |
| 11.0 | 2.1723 |
| 12.0 | 2.1674 |
| 13.0 | 2.162 |
| 14.0 | 2.1563 |
| 15.0 | 2.1504 |
| 16.0 | 2.1442 |
| 17.0 | 2.1377 |
| 18.0 | 2.1309 |
| 19.0 | 2.1236 |
| µm | No |
|---|---|
| 20.0 | 2.1154 |
| 21.0 | 2.1067 |
| 22.0 | 2.0976 |
| 23.0 | 2.0869 |
| 24.0 | 2.0752 |
KRS-6 crystals are grown by the sealed-ampoule Stockbarger technique. Starting materials of the highest purity are selected to ensure that there are no anionic absorption bands between 2 and 16 microns and all crystals are checked for quality by using a pathlength of 120mm. Thallium salts are toxic, and KRS6 has enough solubility to require extreme caution. Careful handling with plastic gloves covered with soft cotton gloves as appropriate to delicate optics is required.
REFERENCES:
(1) Hettner and Leisegang; Optik, V3, p305, 1948
(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