Zinc Sulfide (ZnS) Optical Material
Zinc sulfide is a non-glass, inorganic optical material. It has the highest melting temperature and a moderately high thermal conductivity among non-glass optical ceramics. The graph bars on the material properties cards below compare zinc sulfide 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
75 GPa 11 x 106 psi
Poisson's Ratio
0.28
Thermal Properties
Melting Onset (Solidus)
1830 °C 3330 °F
Specific Heat Capacity
520 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
27 W/m-K 16 BTU/h-ft-°F
Thermal Expansion
6.5 µm/m-K
Otherwise Unclassified Properties
Density
4.1 g/cm3 260 lb/ft3
Light Transmission Range
0.37 to 14 µm
Refractive Index
2.3
Common Calculations
Stiffness to Weight: Axial
10 points
Stiffness to Weight: Bending
34 points
Thermal Diffusivity
13 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