Caesium Bromide CsBr
Download 
Transmission Range
0.25 to 40 μm (1)
Refractive Index
1.6612 at 11 μm (1)
Reflection Loss
11.6% at 11 μm (2 surfaces)
Absorption Coefficient
n/a
Reststrahlen Peak
121.2 μm (2)
dn/dT
-84 x 10-6 K-1 at 0.6 μm (5)
dn/dμ = 0
5.3 μm
Density
4.44 g/cc
Melting Point
636 °C
Thermal Conductivity
0.94 W m-1 K-1 at 273K
Thermal Expansion
47.9 x 10-6 K-1 at 273K
Hardness
Knoop 19.5 with 200g indenter
Specific Heat Capacity
263.8 J Kg-1 K-1 (3)
Dielectric Constant
6.51 at 2 MHz
Youngs Modulus (E)
15.85 GPa (4)
Shear Modulus (G)
7.5 GPa
Bulk Modulus (K)
13.01 GPa
Elastic Coefficients
C11=30.97; C12=4.03; C44=7.5
Apparent Elastic Limit
8.4 MPa (1220 psi) (4)
Poisson Ratio
0.279
Solubility
90g/100ml water at 25°C (See Graph) (6)
Molecular Weight
212.83
Class/Structure
Cubic CsCl, Pm3m, no cleavage planes
| µm | No |
|---|---|
| 0.5 | 1.70896 |
| 1.0 | 1.67793 |
| 2.0 | 1.67061 |
| 3.0 | 1.66901 |
| 4.0 | 1.66813 |
| 5.0 | 1.66737 |
| 6.0 | 1.66659 |
| 7.0 | 1.66573 |
| 8.0 | 1.6477 |
| 9.0 | 1.6637 |
| 10.0 | 1.66251 |
| 11.0 | 1.6612 |
| 12.0 | 1.65976 |
| 13.0 | 1.6582 |
| 14.0 | 1.6561 |
| µm | No |
|---|---|
| 15.0 | 1.65468 |
| 16.0 | 1.65272 |
| 17.0 | 1.65062 |
| 18.0 | 1.64838 |
| 19.0 | 1.646 |
| 20.0 | 1.64348 |
| 21.0 | 1.6408 |
| 22.0 | 1.63798 |
| 23.0 | 1.635 |
| 25.0 | 1.62856 |
| 26.0 | 1.62509 |
| 27.0 | 1.62146 |
| 28.0 | 1.61764 |
| 29.0 | 1.61365 |
| µm | No |
|---|---|
| 30.0 | 1.60947 |
| 31.0 | 1.6051 |
| 32.0 | 1.60053 |
| 33.0 | 1.59576 |
| 34.0 | 1.59078 |
| 35.0 | 1.58558 |
| 36.0 | 1.58016 |
| 37.0 | 1.5745 |
| 38.0 | 1.5686 |
| 39.0 | 1.56245 |
Caesium Bromide is grown by sealed ampoule Stockbarger technique. CsBr is a soft pliable material.
IUPAC International Union of Pure and applied Chemistry recommends the spelling as Cesium. UK Useage is Caesium.
Solubility has historically been quoted as 124g/100mL at 25°C but Crystran Ltd tests 2021 have found this to be inaccurate.
REFERENCES:
(1) Handbook Optical Constants, ed Palik, V3, ISBN 0-12-544423-0
(2) Mitsuishi et al., J Opt Soc. Am. V52, p14, 1962
(3) Kelly, Bureau of Mines Bulletin, No371, p51, 1934
(4) S.Ballard et al; J.Opt.Soc.Am. Vol42, p684, 1952
(5) H.H.Li; J.Phys. Chem. Ref. Data. Vol 5, No 2. 1976
(6) K.Matthews. Crystran Ltd Test Data 2021
