We report nano-scale mechanical heterogeneity of a metallic glass characterized by dynamic atomic force microscopy. Apparent energy dissipation with the variation of ~12%, originating from non-uniform distribution of local viscoelasticity, was characterized. The correlation length of heterogeneous viscoelasticity was measured to be ~2.5{\pm}0.3 nm, which is well consistent with the dimension of shear transformation zones for plastic flow. This study provides the first experimental observation on the nano-scale mechanical heterogeneity in a metallic glass, and may fill the gap between atomic models and the macroscopic properties of metallic glasses.
@article{arxiv.1102.5598,
title = {Characterization of nanoscale mechanical heterogeneity in a metallic glass by dynamic force microscopy},
author = {Y. H. Liu and D. Wang and K. Nakajima and W. Zhang and A. Hirata and T. Nishi and A. Inoue and M. W. Chen},
journal= {arXiv preprint arXiv:1102.5598},
year = {2013}
}