Formula Al2O3
Growth method Czochralski technique
Brigdeman technique
Max. sizes, (mm) Ø150
Transmission range, (_m)
(Thickness 10 mm)
0.17 – 5.0
Structure hexagonal
Density (g/cm3) 3.98
Melting point (° C) 2030
Hardness (Mohs) 9
Thermal expansion coefficient (10-6/K) vertical c-axis: 3.24 – 5.66
Thermal conductivity (W m-1 K-1) vertical c-axis: 23.1
parallel c-axis: 25.2
Specific heat capacity (J kg-1 K-1) 761
Solubility in water (g/100 cm3) 98 x 10-6
Solubility in acids insoluble
Solubility in organic solvents undeclared
Wavelength (_m)
Refractive index n0
ne
1.0
2.0
3.0
4.0
1.7545
1.7374
1.7015
1.6748
1.7460
1.7299
1.6920
1.6679
Absorption coefficient (cm-1) 0.20 at 0.2 µm
0.02 at 0.4 µm
0.46 at 5.0 µm