文摘
Diamond ?100?- and ?111?-oriented nanopillars were fabricated by focused ion beam (FIB) milling from synthetic single crystals and compressed using a larger diameter diamond punch. Uniaxial compressive failure was observed via fracture with a plateau in maximum stress of ~0.25 TPa, the highest uniaxial strength yet measured. This corresponded to maximum shear stresses that converged toward 75 GPa or ~ G/7 at small sizes, which are very close to the ultimate theoretical yield stress estimate of G/2π.