SPI Supplies Magnesium Oxide Single Crystal Wafer, 2 in Dia. x 0.5 mm Thick, 1 side epi-polished
SPI MgO Single Crystal Wafers
2" diameter (0.5 mm thick)
Molecular formula: MgO
Appearance: Optically clear crystalline solid
EC #: 2151719
Molecular Weight: 40.30
1 side epi-polished
Lattice Constant:4.212 Å
Melting Point:2800° C/5072° F
Loss Tangent:9x10-3 @ 10 GHz
Coefficient of Thermal Expansion:8.0 x 10-6/° C (at 100° C)
Hardness (Mohs scale):5.8
Thermal conductivity (C.G.S.):0.09RT
Specific heat constant:0.24
Vicker Hardness (100):910
Refractive Index (60 nm):1.74
Dimensions:2" x 0.5 mm thick
Orientation:(100) ± 1° C
Flatness:Radial flatness is better than 0.0025mm
Surface Roughness:Ra < 0.5nm (typical 0.2 nm)
Rmax < 3.5 nm (typical 2.0 nm)
Polished Side:Double sides epi-ready quality
Package:Paper bag with vacuum
The SPI Supplies MgO Single Crystal Substrate products are used widely for HTSC (high-temperature superconductor) thin film coatings applications worldwide. There is also a growing amount of interest in using these substrates, because of their economic cost, for other applications that previously would not have justified the higher cost of MgO, such as for use as substrates for the III to V elements.
The standard orientation is along the (100) planes. Other orientations at the present time are not available.
The crystals are highly transparent, permitting good transmission down to the UV and IR ranges of the spectrum. No more does the analytical chemist have to use one substrate slide for UV (such as quartz) and another one for IR, with MgO, the same slide can be used for both types of analysis.
New applications are being found outside of the HTSC applications area, for example, in research studying the epitaxial effects of substrates on the crystallization of polymers. Other applications include the deposition of ferro electric thin film coatings on magnesium oxide substrates. And there are also growing applications for MgO in the field of plasma display panel (PDP) technology.
The products are available "epi-polished" on either one side or two sides and are available as standard products in the form of 0.5 mm thick "plates" or wafers (round discs). The most commonly asked for sizes are listed below as "standard" items, however, we can produce our high-quality MgO single crystal substrate materials in just about any size or shape needed, up to 3" (75 mm) diameter or square. They are also available as a standard product in 10 mm cubes. Just let us know your requirements and if in wafer form, whether polished two sides or just one side.
A Note on Moisture Sensitivity:
Because MgO tends to be hygroscopic, the crystals are specially cleaned and packaged. MgO should not be kept in a moist, high humidity environment for prolonged periods of time as this may change the crystalline structure. For storage, it should always be kept in a desiccator environment such as the Secador line of desiccating cabinets.