High Pressure Synthesis of Hard and Superhard Materials

9314020 Badding This work is concerned with the chemistry of covalently bonded hard/superhard materials that are synthesized at high pressure (1 gigapascals to greater than 70 gigapascals), but can be quenched to ambient conditions. These experiments will be performed using diamond-anvil cell techniques together with recently developed methods for the synthesis and characterization of solids at high pressures. Syntheses at extreme pressures and/or temperatures will be combined with detailed in situ observations of the formation and properties of hard materials. The topics to be addressed are the synthesis of diamond and diamond-like materials from novel polycarbyne network-backbone polymers and the synthesis of new hard materials in the carbon-nitrogen and boron-oxygen systems. The goals will be to look for new hard materials, potentially with properties superior or complementary to existing ones and to gain new information about the relationship between crystal structure, chemical composition, and hardness that will help in the design of new hard materials. ***