Lithium Fluoride vs. Potassium Bromide
Both lithium fluoride and potassium bromide are non-glass optical ceramics.
For each property being compared, the top bar is lithium fluoride and the bottom bar is potassium bromide.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 120 | |
| 24 |
| Poisson's Ratio | 0.27 | |
| 0.17 |
| Shear Modulus, GPa | 52 | |
| 7.0 |
Thermal Properties
| Melting Onset (Solidus), °C | 870 | |
| 730 |
| Specific Heat Capacity, J/kg-K | 1560 | |
| 450 |
| Thermal Conductivity, W/m-K | 12 | |
| 4.8 |
| Thermal Expansion, µm/m-K | 32 | |
| 39 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 9.0 | |
| 4.9 |
| Electrical Dissipation At 1 MHz | 0.00020 | |
| 0.00020 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.6 | |
| 2.8 |
| Light Transmission Range, µm | 0.12 to 6.5 | |
| 0.22 to 26 |
| Refractive Index | 1.4 | |
| 1.8 |
Common Calculations
| Stiffness to Weight: Axial, points | 24 | |
| 4.7 |
| Stiffness to Weight: Bending, points | 62 | |
| 35 |
| Thermal Diffusivity, mm2/s | 2.9 | |
| 3.9 |