Vickers hardness*

10,000 kg/mm2

Young's modulus*

1050 GPa

Poisson's ratio

0.1

Density

3.515 g/cm3

Atom density*

1.77×1023 1/cm3

Thermal expansion coefficient

1.0*10-6/K @300K

Sound velocity*

17,500 m/s

Friction coefficient

0.1

Specific heat @ 20°C

0.502 J/gK

Debye temperature*

1860 10K

Bandgap

5.45 eV

Resistivity

1013 - 1016 ohmm

Transmission

225nm to far IR , > 70% @ 10?m

Refractive index

2.38 @ 10?m, 2.41 @ 500nm

Absorption coefficient

0.10 cm-1 @ 10?m

Bandgap

5.45   eV

Tensile strength (0.5mm thick)

Nucleation   surface in tension

Growth   surface in tension

600 MPa

400 MPa

Loss tangent (tan @140 GHz)

< 2.0×10-5

Dielectric   constant

5.7

Dimensions

Thickness

Diameter

10 - 2000 ?m

up to 100 mm

Surface finish

Shape

flat, spherical (convex & concave)

Roughness

< 5 nm*

Flatness

1 fringe/cm*

Wedge

0 – 1°*

Antireflection Coatings (visible and infrared)

Spec. Transmission at 10.6 ?m >98.6 %

Wavefront distortion

< 4 fringes at 633 nm over 30 mm*

Mounting

Diamond windows mounted e.g. in UHV   flanges (bakeable at 250°C, vacuum tight < 10-10 mbar l/s)*