Physics

Amorphous metal

Viscosity

Nanotechnology

Relaxation (psychology)

Diffusion

Viscous liquid

Crystallography

Psychology

Chemical physics

Composite material

Chemistry

Materials science

Atomic diffusion

Molecular physics

Amorphous solid

Social psychology

Thermodynamics

Nature Materials

Revealing the microscopic structural and dynamic pictures of glasses is a long-standing challenge for scientists1,2. Extensive studies on the structure and relaxation dynamics of glasses have constructed the current classical picture3–5: glasses consist of some ‘soft zones’ of loosely bound atoms embedded in a tightly bound atomic matrix. Recent experiments have found an additional fast process in the relaxation spectra6–9, but the underlying physics of this process remains unclear. Here, combining extensive dynamic experiments and computer simulations, we reveal that this fast relaxation is associated with string-like diffusion of liquid-like atoms, which are inherited from the high-temperature liquids. Even at room temperature, some atoms in dense-packed metallic glasses can diffuse just as easily as they would in liquid states, with an experimentally determined viscosity as low as 107 Pa·s. This finding extends our current microscopic picture of glass solids and might help establish the dynamics–property relationship of glasses4. The existence of fast dynamics in glass solids at low temperatures is attributed to liquid-like atoms that are inherited from high-temperature liquids and exhibit behaviour similar to that of atoms in liquid states.

Liquid-like atoms in dense-packed solid glasses