Caesium Bromide (Cesium Bromide) (CsBr)
Cesium Bromide has limited application in the deep IR. Cesium Bromide is slightly more amenable to optical working than CsI and is sometimes used as a beamsplitter component in wide-band spectrophotometers.
|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/°C 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 /°C 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|
To download this data or our MSDS safety data sheet as a pdf, please click on the links at the top of the page. To expand the transmission graphs, please click on the image.
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.
(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