| 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 | 2.2351 |
| 1.0 | 2.2048 |
| 1.5 | 2.2148 |
| 2.0 | 2.2059 |
| 3.0 | 2.1956 |
| 4.0 | 2.1956 |
| 5.0 | 2.1928 |
| 7.0 | 2.1887 |
| 9.0 | 2.1885 |
| 10.0 | 2.1767 |
| 11.0 | 2.1722 |
| 12.0 | 2.1674 |
| 13.0 | 2.1624 |
| 14.0 | 2.1563 |
| 15.0 | 2.1504 |
| 16.0 | 2.1442 |
| 17.0 | 2.1377 |
| 18.0 | 2.1309 |
| 19.0 | 2.1236 |
| 20.0 | 2.1154 |
| 21.0 | 2.1067 |
| 22.0 | 2.0976 |
| 23.0 | 2.0896 |
| 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