MgAl₂O₄ Crystal Substrate

MgAl₂O₄ is an attractive material for uses in a wide range of optical, electronic and structural applications including windows and lenses. Theoretical transmission is very uniform and approaches 87% between 0.3 to 5 microns. Transmission characteristics rival that of ALON and sapphire in the mid-wave IR, making it especially attractive for the ever-increasing performance requirements of current and next-generation IR imaging systems.MgAl₂O₄ magnesium aluminate (spinel) single crystals are widely used in ultrasonic and microwave material and device related epitaxial growth and as fast IC epitaxial substrates.
It is also found that MgAl₂O₄ is a good substrate for III-V nitrides device. Spinel (MgAl₂O₄) is one candidate for such GaN LDs substrate. The crystallographic structure of MgAl₂O₄ is a spinel type (Fd3m), and its lattice constant is 8.083Å. MgAl2O4 is a relatively low-cost substrate material, which has been successfully applied to the growth of high quality GaN films. MgAl₂O₄ is cleaved on the (100) plane. GaN LD cavities have been obtained by simply cleaving MgAl2O4 substrates along the (100) direction, which will also work well for ZnO. MgAl2O4 crystal is very difficult to grow, due to the difficulty in maintaining a single phase structure.