Development of Tunable, Repeatable, Calcium Lanthanum Sulfide Ceramic Powder, Phase II

Lorad Chemical Corporation (ōLoradö) has composed this Phase II full proposal to build off our successes in Phase I and expand our understanding of the Calcium Lanthanum Sulfide (ōCLSö) synthesis to achieve a material that is optimized for densification into infrared transmitting ceramic parts. Lorad has developed nano-scale high purity CLS powders suitable for fabrication of near theoretical density infrared transparent domes/windows and multi-lens applications. CLS incorporated into domes/windows has several applications in infrared (IR) optical systems and IR lenses for sensors, imaging devices, and laser applications. In Phase I of our program, LoradÆs aim was to demonstrate that we could synthesize independent, consistent, repeatable lots of CLS with a tunable non-stoichiometric 90:10 Lanthanum Sulfide to Calcium Sulfide composition. Not only did Lorad achieve this goal, but we were also able to begin addressing a secondary issue with CLS, which is the persistent trace Oxygen and Carbon contamination in the synthesis. Through LoradÆs efforts in Phase I, we were able to greatly reduce the level of Carbon to undetectable levels and made significant inroads in reducing the Oxygen. Our Phase I efforts also led us to learn critical details about the powder morphology and how that relates to the infrared transmission of resultant ceramic parts. During Phase II, Lorad plans to use the information gained from our Phase I program to direct our course of actionŚwe will focus on eliminating any remaining traces of Oxygen and Carbon from the synthesis by modifying conditions of the sulfidation step of the process, we will focus on achieving a rounded particle morphology for the final powder either through post-process milling or a fluidized bed reactor, we will work on further narrowing the particle size distribution to achieve greater uniformity of the pressed ceramic parts, and we will work to further optimize the precursor powder processing so that we can scale-up the batch size of the material. With our greater understanding of CLS obtained through our Phase I program efforts, we are confident that we will achieve production of a powder with the desired characteristics necessary to produce a highly transmissible, densified ceramic part.