Date of this Version
We have investigated anharmonic behavior of Pd by applying systematic nanoscale tensile testing to near defect-free nanowhiskers offering a large range of elastic strain. We measured size-dependent deviations from bulk elastic behavior in nanowhiskers with diameters as small as ∼30 nm. In addition to size-dependent variations in Young’s modulus in the small strain limit, we measured nonlinear elasticity at strains above ∼1%. Both phenomena are attributed to higher-order elasticity in the bulklike core upon being biased from its equilibrium configuration due to the role of surface stresses in small volumes. Quantification of the size-dependent second- and third-order elastic moduli allows for calculation of intrinsic material nonlinearity parameters, e.g., δ. Comparison of the size-independent values of δ in our nanowhiskers with studies on bulk fcc metals lends further insight into the role of length scales on both elastic and plastic mechanical behavior.
Chen, L. Y., Richter, G., Sullivan, J. P., & Gianola, D. S. (2012). Lattice Anharmonicity in Defect-Free Pd Nanowhiskers. Retrieved from https://repository.upenn.edu/mse_papers/219
Date Posted: 27 February 2013
This document has been peer reviewed.