Sapphire (synthetic corundum) Al2O3

Descriptions: Crystallographic :: Optical :: Thermo-physical :: Mechanical :: Chemical

Crystallographic characteristics Al2O3 (sapphire - synthetic corundum)

Syngony
Tetragon
Symmetry Class
3m
Lattice Constants, Angstroms
a=4.758 c=12.991
Cleavability
(1011),(1012), imperfect

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Optical characteristics Al2O3 (sapphire - synthetic corundum)

Refractive Index at ne
1.7771
Refractive Index, nF'-nC'
no
0.0107
Thermal Coefficient of Refractive Index at l=0.46 microns,оС-1
for +/-60оС
bo
(0.88¸1.28)10-5
be
(0.99¸1.39)10-5
Transmission Range, microns (thickness 10мм)
0.17 ¸5.0
Transmittance ti(l) vs. wavelength l

Internal Transmittance ti(l) vs.
wavelength l
l,мкм
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,мкм
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
1.6679

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Thermo-physical characteristics Al2O3 (sapphire - synthetic corundum)

Thermal Linear Expansion at, оС-1 for +/-60оС
^c-axis
(3.24-5.66)10-6
Thermal Conductivity, W/(m оС) at 26 оС
// c-axis
25.2
^c-axis
23.1
Specific Heat Capacity, J/(kg оС) at 18 оС
761
Thermal Stability, оС
162 +/-8
Melting Point, оС
2030

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Mechanical characteristics Al2O3 (sapphire - synthetic corundum)

Density, g/cm3 at 20 оС
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
2.310-12
S12
-0.710-12
S13
-0.410-12
S33
2.210-12
S44
6.810-12
S14
0.510-12
Poisson Ratio
|| to c-axis
0.309
Young Modulus (Е), 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

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Chemical characteristics Al2O3 (sapphire - synthetic corundum)

Solubility Al2O3 ( Sapphire )
in water at 20 оС
g/100cm3
in acids
98*10-6
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