Diamond ( C ) - Cubic Carbon
Diamond ( C ) - Cubic Carbon
APPLICATIONS: Diamond is used for transmission windows and domes.
µm
0.232
0.589
2.0
5.0
20
Transmission Range
Refractive Index
Reflection Loss
Absorption Coefficient
Reststrahlen Peak
dn/dT
dn/dµ = 0
300nm to 2.5µm and 7µm to >100µm (1)
2.4175 @ 0.589µm (1)
30% @ 0.589µm
~0.09 cm-1 @ 10.6µm
n/a
30 x 10-6 /°C @ 300K (3)
n/a
Density
Melting Point
Thermal Conductivity
Thermal Expansion
Hardness
Specific Heat Capacity
Dielectric Constant
Youngs Modulus (E)
Shear Modulus (G)
Bulk Modulus (K)
Elastic Coefficients
Apparent Elastic Limit
Poisson Ratio
3.51
3497°C
2600 W m-1 K-1 @ 273K (2)
1 x 10-6 /°C at 293K
Knoop 5700 to 10400
502 J Kg-1 K-1 @ 300K (4)
5.68 @ 1.68Mhz at 300K (2)
1050 GPa
n/a
442 GPa
C11=1076; C12=125; C44=577
276 MPa
0.16 to 0.29
No
2.6917
2.4175
2.3813
2.3783
2.3741
µm
0.298
0.656
3.0
6.0
No
2.5429
2.4104
2.3795
2.3779
µm
.405
1.00
4.0
10.0
No
2.4626
2.3905
2.3787
2.3765
CVD Diamond
0.5mm
%T
Wavelength µm
Solubility
Insoluble in water
Molecular Weight
12.01
Class/Structure
Cubic Diamond, Fd3m
Diamond is available as single crystal (Type IIa) natural or synthetic or as
polycrystalline CVD film. Single crystal is available economically up to about 4mm
diameter. CVD diamond of 75mm diameter is available. The IR transmission has a
range of absorptions in the mid-IR between 2,5 and 7µms due to inherent lattice
resonances. The UV transmission may be limited to 350nm in poorer quality samples.
Single crystal diamond is selected into four forms:
Ia ~98% of natural yield (>100ppm Nitrogen - yellow)
Ib ~0.1% of natural yield (~100ppm Nitrogen)
IIa ~2% of natural yield (1ppm Nitrogen)
IIb - Synthetic only (100ppm boron for electronic applications)
Only Type IIa is used for optical applications. CVD diamond transmission and
characteristics are very similar to Type IIa.
REFERENCES:
(1) Handbook Optical Constants, ed Palik, V1, ISBN 0-12-544420-6
(2) Properties of Bulk Polycrystalline Diamond, Sussmann et. al. Diamond & Rel.
Mat. 3(1994) 303-312
(3) Fontenella et. al. App. Optics 16, 2949 (1977)
(4) Slack & Bartram J.Appl. Phys. 46, 89 (1975)
Materials Data from Crystran Ltd . Poole . UK
Diamond
Typical transmission
Type IIa Single Crystal Diamond
0.5mm
%T
CVD Diamond
Wavelength nm
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www.crystran.co.uk