Approaching the Limits of Strength: Measuring the Uniaxial Compressive Strength of Diamond at Small Scales

Wheeler, Jeffrey M.; Raghavan, Rejin; Wehrs, Juri; Zhang, Yucheng; Erni, Rolf; Michler, Johann

Nano Letters 16 (2016)

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. (Figure Presented).