38 research outputs found
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 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 (~) of viscosity are possibly close to
this point
Description of Fischer Clusters Formation in Supercooled Liquids Within Framework of Continual Theory of Defects
Liquid is represented as complicated system of disclinations according to
defect description of liquids and glasses. The expressions for the linear
disclination field of an arbitrary form and energy of inter-disclination
interaction are derived in the framework of gauge theory of defects. It allows
us to describe liquid as a disordered system of topological moments and reduce
this model to the Edwards--Anderson model with large-range interaction. Within
the framework of this approach vitrifying is represented as a "hierarchical"
phase transition. The suggested model allows us to explain the process of the
Fischer clusters formation and the slow dynamics in supercooled liquids close
to the liquid--glass transition point
Nonmonotonous relaxation processes in nonequilibrium nanoforming alloys of Al with transition and rare-earth metals
Viscous properties of nickel-containing binary metal melts
The paper presents the results of molecular dynamics study of the viscosity of nickel-containing binary metal melts for a wide range of temperatures, including the region of the equilibrium liquid phase and supercooled melt. It is shown that the temperature dependencies of the viscosity of binary metal melts are described by the Kelton’s quasi-universal model. Based on the analysis of the viscosity coefficient of the binary melt composition within the framework of the Rosenfeld’s scale transformations, it has been established that to correctly describe the viscosity of binary/multicomponent metal melts within the framework of entropy models, it is necessary to use a more complex representation of the excess entropy Sex than in the approximation of pair correlation entropy S