Crystallographic characteristics Al2O3 (sapphire - synthetic corundum)
| Syngony | Tetragon |
|---|---|
|
Symmetry Class |
3m |
|
Lattice Constants, Angstroms |
a=4.758 c=12.991 |
|
Cleavability |
(1011), (1012), imperfect |
Optical characteristics Al2O3 (sapphire - synthetic corundum))
| Refractive Index at ne | 1.7771 | |
|---|---|---|
|
Refractive Index, at nF' nC' |
no |
0.0107 |
|
Thermal Coefficient of Refractive Index at L=046 microns °C-1 for +/-60°C |
bo |
(088,1.28).10-5 |
|
be |
(0.99,1.39).10-5 |
|
|
Transmission Range microns (thickness 10MM) |
0.17,5.5 |
|
|
Transmittance ti (l) vs, wavelength l |
||
| Internal Transmittance ti (l) vs. wavelenght l | |
|---|---|
|
l,MKM |
ti(l) |
|
0.2 |
0.79 |
|
0.5 |
0.97 |
|
1.0 |
0.97 |
|
3.0 |
0.97 |
|
5.0 |
0.45 |
|
Refractive Index n vs. wavelength l |
|
|---|---|
|
l,MKM |
no/ne |
|
0.2 |
|
|
0.5 |
|
|
1.0 |
1.7545 1.7460 |
|
2.0 |
1.7374 1.7299 |
|
3.0 |
1.7015 1.6920 |
|
4.0 |
1.6748 6679 |
Thermo-physical characteristics Al2O3 (sapphire - synthetic corundum)
| Thermal Linear Expansion at, °C-1 for +/-60°C | ^c-axis | (3.24-5.66).10-6 |
|---|---|---|
|
Thermal Conductivity W/(m .°C) at 26 °C |
// c-axis |
25.2 |
|
^c-axis |
23.1 |
|
|
Specific Heat Capacity, J/(kg .°C) at 18 °C |
761 |
|
|
Thermal Stability, °C |
162+/-8 |
|
|
Melting Point, °C |
2030 |
|
Mechanical characteristics Al2O3 (sapphire - synthetic corundum))
| Density, g/cm3 at 20 °C | 3.98 | |
|---|---|---|
|
Mohs Hardness |
9 |
|
|
Vickers Microhardness, Pa |
^to c-axis |
2200. 107 |
|
|| to c-axis |
1940. 107 |
|
|
Constants of Elastic Compliance, Pa-1 |
S11 |
2.3 . 10-12 |
|
S12 |
-0.7 . 10-12 |
|
|
S13 |
-0.4 . 10-12 |
|
|
S33 |
2.2 . 10-12 |
|
|
S44 |
6.8 . 10-12 |
|
|
S14 |
0.5 . 10-12 |
|
|
Poisson Ratio |
|| to c-axis |
0.309 |
|
Young Modulus (E), Pa |
|| to c-axis |
46.26 . 10-10 |
|
^ to c-axis |
42.64 . 10-10 |
|
|
Shear Modulus (G), Pa |
|| to c-axis |
14.43 . 10-10 |
|
^ to c-axis |
16.29 . 10-10 |
|
Chemical characteristics Al2O3 (sapphire - synthetic corundum)
| Solubility Al203 (Sapphire) | |
|---|---|
|
in water at 20 °C g/100cm3 |
in acids |
|
98 * 10-6 |
- |