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Home > Products > Optical Products > Optical Materials > Sapphire |
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Sapphire
| Single crystal Sapphire possesses a unique combination of excellent optical, physical and chemical properties, the most useful is that it is the hardest of the oxide crystals. Sapphire maintains its strength even at high temperatures. It has good thermal properties, excellent electrical and dielectric properties, and is chemically resistant to common acids and alkali at temperatures up to 1000¡ãC as well as to HF below 300¡ãC.
Sapphire is anisotropic hexagonal crystal. Its properties depend on crystallographic direction (relative to the optical C-axis). Large sized sapphire crystals up to 4 inches in diameter are available in TEMTO. TEMTO sapphire crystals are mainly produced by two method¡ª¡ªTGT and Czochraski(CZ) for the highest optical and substrate quality. We also use Verneuil´s mehtod (also called flame fusion method) sapphire for normal optical and substrate quality. |
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| Main Properties |
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| Crystal Properties |
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Crystal Growth Method |
Czochralski (CZ) or TGT
or Verneuil´s (also called flame fusion) |
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Maximum Size |
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Optical Properties
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Transmission Range |
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Reflection Loss, for two surfaces at 5 ¦Ìm |
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dn/dt (@633nm), /K |
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dn/d¦Ì=0 |
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Refractive Index |
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Wavelength (¦Ìm) |
no |
ne |
Wavelength (¦Ìm) |
no |
ne |
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0.185 |
/ |
/ |
0.800 |
1.76013 |
1.75220 |
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0.193 |
1.92879 |
1.91743 |
1.064 |
1.75449 |
1.74663 |
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0.213 |
1.88903 |
1.87839 |
1.320 |
1.75009 |
1.74227 |
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0.226 |
1.87017 |
1.85991 |
1.550
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1.74618 |
1.73838 |
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0.248 |
1.84696 |
1.83719 |
2.010 |
1.73748 |
1.72973 |
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0.266 |
1.83304 |
1.82358 |
2.703 |
1.71900 |
1.71100 |
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0.280
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1.82437
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1.81509 |
3.333 |
1.70100 |
1.69300 |
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0.308
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1.81096
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1.80198 |
3.704 |
1.68700 |
1.67900 |
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0.355
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1.79598
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1.78732
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4.000 |
1.67400 |
1.66600 |
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0.488 |
1.77530 |
1.76711
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4.348 |
1.65800 |
1.65000 |
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0.532 |
1.77170 |
1.76355 |
4.762 |
1.63600 |
1.62800 |
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0.633 |
1.76590 |
1.75787 |
5.000 |
1.62300 |
1.61500 |
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0.780 |
1.76068
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1.75274 |
5.263 |
1.60700 |
1.59900 |
| Transmission Curve |
See Below |
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| Crystallographic Properties |
| Syngony |
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| Crystal Form |
Polycrystalline or Monocrystalline |
| Lattice Constant, Angstrom (Å) |
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| Cleavability |
<1011>, <1012>, imperfect |
| Physical Properties |
| Density, g/cm3 at 20 ¡ãC |
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| Mohs Hardness |
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Dielectric Constant 103-109 Hz at 298 K Parallel to c-axis (//)
Perpendicular to c-axis (¡ª) |
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| Melting point, ¡ãC |
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Thermal Conductivity, W/m¡¤K at at 300 K
Parallel to c-axis (//)
Perpendicular to c-axis (¡ª) |
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Thermal Expansion, 1/K at 298 K
Parallel to c-axis (//)
Perpendicular to c-axis (¡ª) |
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| Specific Heat Capacity, Wxs/g/k |
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| Bandgap, eV |
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| Knoop Hardness, Kg/mm2 |
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| Youngs Modulus, Gpa |
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| Shear Modulus, GPan |
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| Bulk Modulus, Gpa at 273 K |
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| Poissons Ratio |
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| Elastic Coefficient |
C11=496, C12=164, C13=115, C33=498, C44=148 |
| Apparent Elastic Limit |
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| Chemical Properties |
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Chemical Formula |
Al2O3 |
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Molecular Weight |
101.94 |
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Solubility in water at 20¡ãC, g/100cm3 |
98x10-6 |
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Solubility in acids |
Soluble | | |
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