Compressive Strength of Diamond from First-Principles Calculation

Compressive strength, like tensile and shear strength, is one of the intrinsic mechanical properties of solid materials. We investigated the ideal compressive strength and corresponding compressive deformation of diamond using pseudopotential density functional theory. The calculated uniaxial compressive strength of diamond is −223.1, −469.0, and −470.4 GPa along the ⟨100⟩, ⟨110⟩, and ⟨111⟩ directions, respectively. The elastic deformation of diamond in compressive strain below the proportional limit of 17% has been determined from the perfect linear response between strain and stress along the ⟨100⟩ direction. The present work should be helpful to the understanding of the compressive property of diamond and to the explanation of the limit strength of diamond anvil cell.