|
Sapphire is a single crystal aluminum oxide
(Al2O3). It is one of the hardest materials.
Sapphire has good transmission characteristics
over the visible, and near IR spectrum. It
exhibits high mechanical strength, chemical
resistance, thermal conductivity and thermal
stability. It is often used as window materials in
specific field such as space technology where
scratch or high temperature resistance is
required.
Properties:
- Transparence range: 0.18- 4.5μm
- Density: 3.98g/cm3
- Mohs hardness: 9
- Melting point: 2030oC
- Thermal conductivity: 0.04W/m/K
- Expansion coefficient: 8.4x10-6/K
- Refractive Index: 1.755@1µm
Transmission Curve:
|
Physical Properties |
|
| Crystal
Symmetry |
Hexagonal |
| Lattice
constant |
a
=4.75 Å
c =12.97 Å |
| Transparence
range |
0.18-
4.5 μm |
| Density |
3.98g/cm3 |
| Mohs hardness |
9 |
| Melting point |
2030oC |
| Thermal
conductivity |
0.04
W/m/K |
| Expansion
coefficient (10-6/K) |
8.4 |
| Refractive
Index (1.0
μm) |
1.755 |
|
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