Structural transitions and nonmonotonic relaxation processes in liquid metals.

Structural transitions in melts as well as their dynamics are considered. It is supposed that liquid represents the solution of relatively stable solidlike locally favored structures 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 transition 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 oscillatinglike time behavior (omega approximately 10(-2) s(-1)) of viscosity are possibly close to this point.