Note: Special care should be taken when handling Zinc Selenide as it is a toxic material. Always wear rubber or plastic gloves to avoid risk of contamination.
Zinc Selenide (ZnSe)
Zinc Selenide (ZnSe) is a popular material in infrared applications. Very wide transmission spectrum, covering the range from 0.6 μm to 22 μm and the high quality of material obtained by CVD (Chemical Vapor Deposition), make it usefull for the production of optical elements (windows, lenses, mirrors) for infrared applications (thermal imaging, FLIR, medical systems, high power IR lasers). Zinc Selenide is produced by synthesis from Zinc vapour and H2Se gas, forming as sheets on Graphite susceptors. Zinc Selenide is microcrystalline in structure, the grain size being controlled to produce maximum strength. Single crystal ZnSe is available, but is not common but has been reported as having lower absorption and thus more effective for CO2 optics. This chemically vapor deposited material has wide usage in high power CO2 laser systems because of its low absorption coefficient and high resistance to thermal shock.
Zinc Selenide oxidizes significantly at 300°C, exhibits plastic deformation at about 500°C and dissociates about 700°C. For safety, Zinc Selenide windows should not be used above 250°C in normal atmosphere.
Zinc Selenide (ZnSe) is a relatively soft material that scratches easily and it is not recommended in harsh environments because its Knoop Hardness is only 120. When handling, apply uniform pressure and wear Latex finger cots or gloves to prevent contamination.
|Transmission Range :||0.6 to 21.0 μm|
|Refractive Index :||2.4028 at 10.6 μm|
|Reflection Loss :||29.1% at 10.6 μm (2 surfaces)|
|Absorption Coefficient :||0.0005 cm-1 at 10.6 μm|
|Reststrahlen Peak :||45.7 μm|
|dn/dT :||+61 x 10-6/°C at 10.6 μm at 298K|
|dn/dμ = 0 :||5.5 μm|
|Density :||5.27 g/cc|
|Melting Point :||1525°C (see notes below)|
|Thermal Conductivity :||18 W m-1 K-1 at 298K|
|Thermal Expansion :||7.1 x 10-6 /°C at 273K|
|Hardness :||Knoop 120 with 50g indenter|
|Specific Heat Capacity :||339 J Kg-1 K-1|
|Dielectric Constant :||n/a|
|Youngs Modulus (E) :||67.2 GPa|
|Shear Modulus (G) :||n/a|
|Bulk Modulus (K) :||40 GPa|
|Elastic Coefficients :||Not Available|
|Apparent Elastic Limit :||55.1 MPa (8000 psi)|
|Poisson Ratio :||0.28|
|Solubility :||0.001g/100g water|
|Molecular Weight :||144.33|
|Class/Structure :||HIP polycrystalline cubic, ZnS, F43m|
While every attempt has been made to verify the source of the information, no responsibility is accepted for accuracy of data.