Elastic properties of nanopolycrystalline diamond: The nature of ultrahigh stiffness

摘要

Recent experimental reports on the production of nanopolycrystalline diamond with outstanding mechanical stiffness highlight the importance of theoretical investigation of this unusual effect. Here, we provide the comprehensive theoretical investigation of such material. We traced the evolution of the nanopolycrystalline diamond stiffness characterized by bulk modulus with the grain size increasing up to 10 nm and found samples with bulk modulus higher than that of diamond. We studied nature of such specific behavior and proposed a mechanism of stiffening in nanopolvcrystalline diamond which could explain reference experimental results.