Structural transitions and nonmonotonic relaxation processes in liquid metals

TL;DR

This paper investigates structural transitions and complex relaxation behaviors in liquid metals, proposing that liquid-liquid transitions involve cooperative bond ordering and lead to nonmonotonic viscosity relaxation.

Contribution

It introduces a model linking liquid-liquid transitions in metals to cooperative medium-range bond ordering and explains oscillating relaxation processes.

Findings

Step changes in Co viscosity as liquid-liquid transitions.

Relaxation processes with oscillating-like behavior near transition points.

Transition from Newtonian to structured fluid states.

Abstract

Structural transitions in melts as well as their dynamics are considered. It is supposed that liquid represents the solution of relatively stable solid-like locally favored structures (LFS) in the surrounding of disordered normal-liquid structures. Within the framework of this approach the step changes of liquid Co viscosity are considered as liquid-liquid transitions. It is supposed that this sort of transitions represents the cooperative medium-range bond ordering, and corresponds to the transition of the "Newtonian fluid" to the "structured fluid". It is shown that relaxation processes with oscillating-like time behavior ($\omega \sim 10^{-2}$~$s^{-1}$) of viscosity are possibly close to this point.