New Hard and Superhard Materials: RhB_(1.1) and IrB_(1.35)

摘要

Hard and superhard materials possess a combination of outstanding properties, such as high elastic modulus and hardness, scratch resistance, chemical stability, and the ability to sustain extreme differential stresses, which makes them promising materials for various technological applications. Nowadays, the experimental and theoretical efforts are focused on the design and discovery of new superhard materials. Hardness is a measure of structural stability, which is in turn determined by elastic stiffness and plastic resistance, which depend on bonding type (electronic structure). Two design parameters are of utmost importance for the selection of superhard compounds, i.e., a high valence electron density and the presence of covalent bonding.