Zinc Sulfide (ZnS)

Zinc Sulfide (ZnS)

ZnS grown by chemical vapor desposition (CVD) at II-VI Infrared exhibits exceptional fracture strength and hardness leading to its frequent choice for military applications or other harsh environments. This material is often used in the 8 to 12 microns region. Its high resistance to rain erosion and high-speed dust and particulate abrasion makes it particularly suitable for exterior IR windows on aircraft frames.

ZnS has a lower cost relative to ZnSe and ZnS MS, and has potential wherever a tough and strong IR transmitting material is required.

ZnS Transmission Graphs

Material Properties

Optical Properties
Bulk Absorption Coefficient @ 10.6µm	<= 0.24 cm^-1
Temperature Change of Refractive Index @ 10.6µm	41 x 10^-6/°C
Refractive Index Inhomogeneity @ 10.6µm	< 100 x 10^-6

Thermal Properties
Thermal Conductivity @ 20° C	0.167 W/cm/°C
Specific Heat	0.469 J/g/°C
Linear Expansion Coefficient @ 20° C	6.8 x10^-6/°C

Mechanical Properties
Young’s Modulus	74.5 GPa (10.8 x 10⁶ psi)
Rupture Modulus	103.4 MPa (15,000 psi)
Knoop Hardness	210-240 kg/mm²
Density	4.08 g/cm³
Poisson’s Ratio	0.27

Wavelength (µm)	Index	Wavelength (µm)	Index	Wavelength (µm)	Index	Wavelength (µm)	Index
0.42	2.516	1.0	2.292	7.0	2.232	13.0	2.152
0.46	2.458	1.4	2.275	7.4	2.228	13.4	2.143
0.50	2.419	1.8	2.267	7.8	2.225	13.8	2.135
0.54	2.391	2.2	2.263	8.2	2.221	14.2	2.126
0.58	2.371	2.6	2.260	8.6	2.217	14.6	2.116
0.62	2.355	3.0	2.257	9.0	2.212	15.0	2.106
0.66	2.342	3.4	2.255	9.4	2.208	15.4	2.095
0.70	2.332	3.8	2.253	9.8	2.203	15.8	2.084
0.74	2.323	4.2	2.251	10.2	2.198	16.2	2.072
0.78	2.316	4.6	2.248	10.6	2.192	16.6	2.059
0.82	2.310	5.0	2.246	11.0	2.186	17.0	2.045
0.86	2.305	5.4	2.244	11.4	2.180	17.4	2.030
0.90	2.301	5.8	2.241	11.8	2.173	17.8	2.015
0.94	2.297	6.2	2.238	12.2	2.167	18.2	1.998
0.98	2.294	6.6	2.235	12.6	2.159