There is a need for an infrared window material that can replace single crystal sapphire in airborne applications. In order to do so, the alternate must possess optical transmission, optical scatter, mechanical strength, and mechanical stiffness comparable to sapphire while costing significantly less than sapphire. Nanocerox proposes to utilize its extensive experience in processing YAG to create a material solution to this need. While YAG exhibits intrinsic absorption between 4 and 5 microns, reduction of this absorption may be possible via mixed garnet compositions containing Gd and/or Ga. Nanocerox will investigate these materials, optimize optical, mechanical, and price performance in the system, then make witness coupons of the optimum composition for mechanical and optical testing. An option task is proposed to optimize Nanocerox slip casting techniques for mixed garnet window materials.
Benefit: The outcome of the proposed work will be a polycrystalline alternative to single crystal sapphire that exhibits optical and mechanical properties necessary for use in airborne military applications. Garnet materials and the techniques to process them into transparent polycrystalline ceramics are also particularly useful as laser gain media.
Keywords: flame spray pyrolysis, flame spray pyrolysis, ceramic, nanopowder, YAG, garnet, intrinsic absorption
