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 Lett · 2016

basic_science · Level V

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Abstract

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.