Cesium Bromide (CsBr) Optical Material
Cesium bromide is a non-glass, inorganic optical material. It has a fairly low thermal conductivity among non-glass optical ceramics. In addition, it has a moderately low heat capacity and a moderately low melting temperature. The graph bars on the material properties cards below compare cesium bromide to other non-glass optical ceramics (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
16 GPa 2.3 x 106 psi
Knoop Hardness
20
Poisson's Ratio
0.28
Shear Modulus
7.5 GPa 1.1 x 106 psi
Thermal Properties
Melting Onset (Solidus)
640 °C 1180 °F
Specific Heat Capacity
270 J/kg-K 0.063 BTU/lb-°F
Thermal Conductivity
0.9 W/m-K 0.52 BTU/h-ft-°F
Thermal Expansion
48 µm/m-K
Otherwise Unclassified Properties
Density
4.4 g/cm3 280 lb/ft3
Light Transmission Range
0.25 to 40 µm
Refractive Index
1.6
Common Calculations
Stiffness to Weight: Axial
2.0 points
Stiffness to Weight: Bending
19 points
Thermal Diffusivity
0.76 mm2/s
Followup Questions
Further Reading
Handbook of Optical Materials, Marvin J. Weber, 2003
Handbook of Optical Constants of Solids, Edward D. Palik (editor), 1998