[Download]Name: Cao C R et al. (2019) Liquid-like behaviours of metallic glassy nanoparticles at room temperature
Direct atomic-scale observations and measurements on dynamics of amorphous metallic nanoparticles (a-NPs) are challenging owing to the insufﬁcient consciousness to their striking characterizations and the difﬁculties in technological approaches. In this study, we observe coalescence process of the a-NPs at atomic scale. We measure the viscosity of the a-NPs through the particles coalescence by in situ method. We ﬁnd that the a-NPs have fast dynamics, and the viscosity of the a-NPs exhibits a power law relationship with size of the aNPs. The a-NPs with sizes smaller than 3nm are in a supercooled liquid state and exhibit liquid-like behaviours with a decreased viscosity by four orders of magnitude lower than that of bulk glasses. These results reveal the intrinsic ﬂow characteristics of glasses in low demension, and pave a way to understand the liquid-like behaviours of low dimension glass, and are also of key interest to develop size-controlled nanodevices.