Softening Effect on Elastic Moduli of Fe, Nb, Cu, and RuAl Nanoparticles.

ABSTRACT

Using the embedded-atom method, the elastic moduli as a function of the size of Fe, Nb, Cu and RuAl nanoparticles were investigated. By decreasing particle size, a decrease in moduli was observed, and the softening of the modulus correlated with the inverse Hall-Petch relation. This softening mechanism of a nanomaterial might be attributable to easy movement of the internal/surface dislocations of a grain at a low shear modulus. The effect of size on the physical properties of the nanoparticles (>5.0 nm) was found to be smaller than those of the particles (<5.0 nm). It was concluded that nanograins larger than 5 nm have elastic moduli to be approximately equal to ones of their bulk counterpart.