Sapphire is a single crystal aluminum oxide (Al2O3). Its Mohs hardness is 9, it is one of the hardest materials. Sapphire has good mechanical strength, and it is also transparent from visible to IR spectrum. So, it is always used as window material where scratch resistance is required.
- Lattice Constant: a =4.75 A; c =12.97A
- Transparent Range: 180nm ~ 4500nm
- Density: 3.98g/cm3
- Mohs Hardness: 9
- Melting Point: 2030℃
- Thermal Conductivity: 0.04W/m/K
- Expansion Coefficient: 8.4x10-6/K
- Refractive Index: 1.755@1um
Note: Other optical material can also be provided by Union Optic, please contact us for details.