Sappire (as known as white sappire, molecular formula Al2O3) single crystal is an excellent multifunctional material. It has high temperature resistance, good thermal conductivity, high hardness, infrared transmission and good chemical stability. It is widely used in many fields of industry, national defense and scientific research (such as high-temperature infrared windows, etc.). At the same time, it is also a widely used single crystal substrate material, and it is the first choice for the blue, violet, and white light emitting diode (LED) and blue laser (LD) industries. And it is also an important superconducting film substrate. In addition to making Y-series, La-series and other high-temperature superconducting films, it can also be used to grow new practical MgB2 superconducting films.
| Main Property Parameters | |||
| Crystal System | Hexagonal | ||
| Crystal Lattice Constant | a=4.748Å c=12.97Å | ||
| Density | 3.98（g/cm3） | ||
| Melt Point | 2040℃ | ||
| Growth Method | Czochralski, Kyropoulos | ||
| Mohs Hardness | 9 | ||
| Refractive Index | 300K， ∥C，1.762 @630nm ⊥C，1.770 @630nm | ||
| Thermal Expansion | 5.8x10-6/K | ||
| Thermal Conductivity（K/(°cm.s)） | ⊥c | //c | |
| 23℃ | 0.055 | 26℃ 0.060 | |
| 77℃ | 0.040 | 70℃ 0.041 | |
| Loss Tangent at 293K | 1×10-4（1MHz） | ||
| Dielectric Constant at 103—109Hz @25℃ | ∥C，11.5 ⊥C，9.3 | ||
| Transmittance | 80％@ 400~4000nm | ||
| Crystal Direction | A-plane | <11-20> | 2.379A |
| R-plane | <1-102> | 1.740A | |
| M-plane | <10-10> | 1.375A | |
| C-plane | <0001> | 2.165A | |
| Crystallographic Orientation Tolerance | ±0.5° | ||
| Regular Size and Tolerance | 10×3,10×5，10×10,15×15，20×15，20×20， | ||
| Regular Thickness and Tolerance | 0.5mm，1.0mm | ||
| Polishing | One side or two sides | ||
| Surface Roughness | Ra<5Å（5×5μm） | ||
| Packaging | Clean bag (100), Super clean room (1000) | ||
