%0 Journal Article
%T Bulk metallic glass-like structure of small icosahedral metallic nanoparticles
%A Vicky V. T. Doan-Nguyen
%A Simon A. J. Kimber
%A Diego Pontoni
%A Benjamin T. Diroll
%A Danielle C. Reifsnyder
%A Marcel Miglierini
%A Xiaohao Yang
%A Christopher B. Murray
%A Simon J. L. Billinge
%J Physics
%D 2013
%I arXiv
%R 10.1021/nn501591g
%X We demonstrate a remarkable equivalence in structure measured by total X-ray scattering methods between very small metallic nanoparticles and bulk metallic glasses (BMGs), thus connecting two disparate fields, shedding new light on both. Our results show that for nanoparticle diameters <5 nm the structure of Ni nanoparticles changes from fcc to the characteristic BMG-like structure, despite them being formed from a single element, an effect we call nano-metallic glass (NMG) formation. However, high-resolution TEM images of the NMG clusters exhibit lattice fringes indicating a locally well-ordered, rather than glassy, structure. These seemingly contradictory results may be reconciled by finding a locally ordered structure that is highly isotropic and we show that local icosahedral packing within 5 atomic shells explains this. Since this structure is stabilized only in the vicinity of a surface which highlights the importance of the presence of free volume in BMGs for stabilizing similar local clusters.
%U http://arxiv.org/abs/1305.7261v2