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℃ as well as to HF below 300℃.

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 Rising EO. Rising EO’s sapphire crystals are produced by two method——TGT and Czochraski for the highest optical and substrate quality.

Transmission Curve	See below
Crystallographic properties
Syngony	Hexagonal System
Crystal Form	Poly or Single Crystal
Lattice Constant, ?	7a=4.785, c=12.991
Cleavability	<1011>, <1012>, imperfect
Physical properties
Density, g/cm3 at 20 оС	3.98
Hardness, Mohs	9
Dielectric Constant 102-108 Hz at 298 K Parallel to c-axis (//) Perpendicular to c-axis (— )	10.55 8.6
Melting point, оС	2042
Thermal Conductivity, W/m·K at at 300 K Parallel to c-axis (//) Perpendicular to c-axis (— )	35.1 33.0
Thermal Expansion, 1/K at 298 K Parallel to c-axis (//) Perpendicular to c-axis (— )	5.6 × 10-6 5.0 × 10-6
Specific Heat Capacity, W×s/g/k	0.418
Bandgap, eV	9.9
Knoop Hardness, kg/mm2	1370
Young's Modulus, Gpa	335
Shear Modulus, GPan	148
Bulk Modulus, Gpa at 273 K	240
Poisson's Ratio	0.25
Elastic Coefficient	C11=496, C12=164, C13=115, C33=498, C44=148
Apparent Elastic Limit	275 MPa (13000psi)

Main Applications

These properties encourage the use of Sapphire in aggressive environments where reliability, optical transmission or strength is required. It is have the following wide applications in the range from the vacuum ultraviolet to the near infrared:

Optical applications:

Illumination windows
Sapphire light guides
LCD projector windows
Optical components

such as lenses, prisms, other laser and infrared optics

Medical applications:

Surgical tips
Endoscope lenses

Analytical applications:
Used in very high-pressure applications in replacement of glass or quartz tubes in NMR
Sapphire replaces quartz to improve durability and reduce contamination in mass spectroscopy

Aerospace applications:
Windows for sensors
Infrared Countermeasure lamps

Electronic applications: Sapphire substrate with different orientation has different applications:
1 (0001) Basal Plane Sapphire Substrate:
Epitaxial Gallium Nitride chip for blue LED
IR detector

2 (-1 1 0 2) R-Plane Sapphire Substrate:
GaAs wafer carriers
Microwave IC
SOS (Silicon on Sapphire)- High Speed IC
Pressure Transducer

3 (1 -1 2 0) A Plane Sapphire Substrate:
The growth of high Te superconductors

General Specifications