Materials: Zinc Sulfide

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.

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