Sapphire
 | Product SpecificationsSapphire | |
| Mechanical Properties | ||
| Density | 3.97g/cm3 | |
| Vickers Hardness ∥ to c-axis | 1940 | |
| Vickers Hardness ⊥ to c-axis | 2200 | |
| Tensile Strength | 60,000 psi | |
| Compressive Strength | 300,000 psi | |
| Young’s Modulus | 74 x 106 psi | |
| Poisson Ratio | 0.28 | |
| Thermal Properties | ||
| Melting Point | 2050°C | |
| Thermal Conductivity | 32W/Mk (@258°C) | |
| Specific Heat | 1.99 J/cm3°C) | |
| Electrical Properties | ||
| Resistivity | @25°C > 1018 ohm cm @500°C > 1012 ohm cm | |
| Dielectric Constant | Perpendicular to C axis 9.3 (KHz-I GHz, 25°) Parallel to C axis 11.5 (KHz-I GHz, 25°) | |
| Dielectric Strength | 480,000 v/cm | |
| Optical Properties | ||
| Near and Mid-wave IR transmission | >86% | |
| UV transmission | >70% | |
| Refractive Index | 1.83 @ 0.26 μm 1.76 @ 0.63 μm 1.58 @ 05.57 μm | |
| Birefringence | 0.0087 @ 0.55 μm | |
As the second hardest material in nature after diamond, and with exceptional optical qualities, physical strength, resistance to impact, abrasion and corrosion, durability under extreme pressure and temperature, bio-compatibility and chemical inertness, sapphire is an ideal base material for deposition of semiconductor materials for manufacturing optical and electronic devices. Its ability to be fashioned into nearly any shape for a variety of applications and its electrical and material properties make it the predominant base material on which to produce LEDs, as well as the only base substrate material used in Silicon on Sapphire RFICs.