A universal scaling law for the strength of metal micropillars and nanowires

The yield strength of sub-micron single-crystal metal pillars and wires increases with decreasing pillar diameter. Here, we show that the yield stress (resolved onto a slip system), σrss, scaled by shear modulus, μ, and the diameter, d, scaled by Burgers vector, b  , shows the following universal correlation: σrss/μ=A(d/b)mσrss/μ=A(d/b)m; for face-centred cubic (fcc) metals A = 0.71 and m = −0.66. Data for Mo and a Mo alloy are found to approximately obey the fcc correlation, despite having a different crystal structure.