Material - Zinc Sulphide (ZnS)
Zinc Sulphide (ZnS) is used for manufacturing of infrared IR optics: ZnS windows and ZnS lenses in spectral range (0.4 - 13.5) microns where maximum transmission and lowest absorption is required, and also selected for use where visible alignment is an advantage.
To obtain high transmittance ZnS crystals are grown by Chemical Vapor Deposition process (CVD). CVD Zinc Sulphide is polycrystalline material which is used in the optical components in infrared IR optical devices.
ZnS (Zinc Sulphide) Chemical Vapor Deposition (CVD) material is produced by synthesis from zinc vapour and H2S gas, forming as sheets on graphite susceptors (CVD-ZnS processes). CVD-ZnS has a polycrystalline structure; the grain size of CVD Zinc Sulphide material is controlled to produce maximum strength and machinability.
ZnS (Zinc Sulphide) multispectral grade is then Hot Isostatically Pressed (HIP) to improve the mid IR transmission and produce the visibly clear form. Polycrystal ZnS is available.
Crystaltechno Ltd.
- grows Zinc Sulphide (CVD ZnS ) ingots transparent in the spectral range (0.37 - 13.5) microns.
- manufactures from Zinc Sulphide (CVD ZnS ) the following optics: blanks, protective plates, windows, domes, wedges, lenses and meniscus These products are used for infrared applications.
Spectral Transmittance (T) of CVD-ZnS Uncoated Polished Window thickness 5mm for range (200 - 1100) nm and for range (2.5 - 25) microns.
You can order the different ZnS optics from CVD ZnS material.
Crystaltechno Ltd. offers the manufacturing of ZnS optics (in detail please see Catalog):
Perhaps you will find required ZnSe optics at our stock, please see item Optical Crystals.
BASE PROPERTIES
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PARAMETER |
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VALUE |
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| OPTICAL |
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| |
ZnS Transmission Range |
|
0.37 to 13.5 microns |
|
| |
Refractive Index |
|
2.20084 at 10 microns |
|
| |
Reflection Loss |
|
26.2% at 10 µm (2 surfaces) |
|
| |
dn/dT |
|
+38.7 x 10-6/°C at 3.39µm |
|
| |
Index of Absorption |
|
0.0006 cm-1 at 3.8 microns |
|
| |
Restrahlen Peak |
|
30.5 microns |
|
| PHYSICAL |
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| |
Density |
|
4.09 g/cm3 |
|
| |
Melting Point |
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1765 °C (dissociates about 700°C)° C |
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| |
Thermal Conductivity |
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27.2 Wm-1K-1 at 298K |
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| |
Thermal Expansion |
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6.5 x 10-6/°C at 273K |
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| |
Hardness |
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Knoop 160 with 50g indenter |
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| |
Specific Heat Capacity |
|
515 J/(kg K) |
|
| |
Dielectric Constant |
|
8 |
|
| |
Young's Modulus (E) |
|
74.5 GPa |
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| |
Apparent Elastic Limit |
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68.9 MPa (10,000psi) |
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| |
Poisson Ratio |
|
0.28 |
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| CHEMICAL |
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| |
Solubility |
|
0.001 g/100g water |
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| |
Molecular Weight |
|
144.33 |
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| |
Class/Structure |
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HIP polycrystalline cubic, ZnS, F43m |
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REFRACTIVE INDEX
| |
Wavelength, µm |
0.405 |
0.436 |
0.468 |
0.480 |
0.509 |
0.546 |
0.588 |
0.644 |
0.668 |
0.706 |
|
|
Refractive Index od ZnS |
2.545 |
2.489 |
2.449 |
2.437 |
2.413 |
2.388 |
2.368 |
2.347 |
2.340 |
2.331 |
|
|
|
|
|
|
|
|
|
|
| |
Wavelength, µm |
0.780 |
0.795 |
0.852 |
0.894 |
1.014 |
1.129 |
1.530 |
2.058 |
3.000 |
3.500 |
|
|
Refractive Index of Zinc Sulfide |
2.317 |
2.314 |
2.306 |
2.302 |
2.292 |
2.285 |
2.272 |
2.264 |
2.258 |
2.255 |
|
|
|
|
|
|
|
|
|
|
| |
Wavelength, µm |
4.000 |
4.500 |
5.000 |
8.000 |
9.000 |
10.00 |
11.25 |
12.00 |
13.00 |
|
|
|
Refractive Index |
2.252 |
2.250 |
2.247 |
2.223 |
2.213 |
2.201 |
2.183 |
2.171 |
2.153 |
|
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