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α-Al2O3
(Sapphire)
Sapphire is an
excellent multi-functional material, it has high thermal conductivity, hardness,
IR transmission, high stability in different chemical atmosphere and is able to
stand high temperature, so it is widely used in many areas like science,
technology, industry and defense. It is an important substrate material for
blue, violet, UV and white LED and LD as well as for high Tc superconductive
films. Except Y-system, La-system superconductive films, the new superconductive
material, MgB film, can also be grown on it while most substrates will be
chemical damaged during the film growth process by the chemical atmosphere.
Crystalline Attributes:
|
Crystal structure |
3 m |
|
Cell parameter |
a=4.758 Å c=12.983 Å |
|
Melting point |
2325oK |
|
Density |
3.99g/cm3 |
|
Specific Heat |
0.757J/g.k |
|
Thermal conductivity |
35.1
∥c
33.0 ⊥c
W/m.k |
|
Thermal expansion
(10-6k-1) |
4.3∥a,3.9∥c(294oK)
9.2∥a,9.3∥c(757oK) |
|
Dielectric constant (εr) |
9.4∥a,11.5∥c(295oK)
9.3∥a,11.3∥c(80oK)
|
|
Dielectric loss
(tgδ) |
<1x10-6(80oK)
Microwave |
|
Hardness
(Mohs) |
9 |
|
Growth Method |
Czokralski |
Substrate Specifications:
Standard
Size: Ф2″,Ф1″, 20x20，10x10，10x5，10x3mm…
Thickness: 0.5mm，1.0mm.
Thickness tolerance: +/-0.02mm or 0.005mm for special order;
Polish: one or two sides
Orientation：<10-10>
, <1-102> , <11-20>, <0001>
Orientation accuracy: +/-0.5o
Edge Orientation accuracy: 2o（or
1ofor
special order）
Cut with special tilt angle: available(tilt angle:1o－45o)
Micro roughness Ra;≤5Å(5μmx5μm)
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