|
 |
|
CVD Diamond:
Properties
|
|
 General
properties
Demonstrated
properties
Optical
properties
Thermal
properties
Mechanical
properties
Dielectric
properties
|
|
|
|
Diamond
has a unique combination of optical, thermal, mechanical and
electronic properties that can be useful for a number of technical
applications:
|
|
General Properties |
|
Property |
|
Value |
|
|
|
|
|
Hardness* |
|
10,000 kg/mm2
|
|
Strength, tensile
| |
>1.2 GPa
|
|
|
Sound velocity*
| |
17,500 m/s
|
|
|
Density
| |
3.52 g/cm3
|
|
|
Atom density*
| |
1.77×1023 1/cm3
|
|
|
Young's modulus*
| |
1140 GPa
|
|
|
Poisson's ratio
| |
0.069
|
|
|
Thermal expansion coefficient
| |
1.1 ppm/K
|
|
|
Thermal conductivity*
| |
20.0 W/cmK
|
|
|
Debye temperature*
| |
2,220 K
|
|
|
Refractive index
| |
2.41
|
|
|
Optical transparency
| |
UV to far IR |
|
|
Loss tangent at 140 GHz
| |
< 10-5
|
|
|
Dielectric constant
| |
5.7
|
|
|
Dielectric strength
| |
10,000,000 V/m
|
|
|
Electron mobility
| |
2,200 cm2/Vs
|
|
|
Hole mobility
| |
1,600 cm2/Vs
|
|
|
Bandgap
| |
5.45 eV
|
|
|
Resistivity
| |
1013 - 1016 Wcm
|
|
|
*highest value of all solid materials
|
|
Demonstrated Properties |
|
At the
Fraunhofer Institut IAF we have specialized in the preparation of
high-quality CVD diamond disks. The properties of these disks
approach those of perfect natural diamond crystals. In particular,
we have demonstrated: |
|
Demonstrated properties
|
|
|
Thermal properties |
Thermal conductivity
k = 21.5 W/cmK at 20°C,
k = 54.0 W/cmK at -150°C
Thermal expansion
1.0 ppm/K at 20°C
1.6 ppm/K at 100°C
2.3 ppm/K at 200°C
3.5 ppm/K at 400°C
|
|
|
Mechanical properties |
Fracture strength
800 MPa at 200 µm thickness
400 MPa at 800 µm thickness
Young's modulus
1000 GPa
|
|
|
Optical properties |
Optical absorption
< 0.04 cm-1 (10.6 µm)
Optical scattering
< 0.8 % (633 nm, BDTF 2°-80°)
|
|
|
Dielectric properties |
Loss tangent
tan d = 1-2×10-5 at
140 GHz |
|
|
|
| |
|
|
|
|
