Orientation dependences of atomic structures in chemically heterogeneous Cu50Ta50/Ta glass-crystal interfaces
GQ Yang and XZ Gao and JF Li and LT Kong, JOURNAL OF APPLIED PHYSICS, 117, 015303 (2015).
Molecular dynamics simulations based on an angular-dependent potential were performed to examine the structural properties of chemically heterogeneous interfaces between amorphous Cu50Ta50 and crystalline Ta. Several phenomena, namely, layering, crystallization, intermixing, and composition segregation, were observed in the Cu50Ta50 region adjacent to the Ta layers. These interfacial behaviors are found to depend on the orientation of the underlying Ta substrate: Layering induced by Ta(110) extends the farthest into Cu50Ta50, crystallization in the Cu50Ta50 region is most significant for interface against Ta(100), while inter- diffusion is most pronounced for Ta(111). It turns out that the induced layering behavior is dominated by the interlayer distances of the underlying Ta layers, while the degree of inter-diffusion is governed by the openness of the Ta crystalline layers. In addition, composition segregations are observed in all interface models, corresponding to the immiscible nature of the Cu-Ta system. Furthermore, Voronoi polyhedra < 0,5,2,6 > and < 0,4,4,6 > are found to be abundant in the vicinity of the interfaces for all models, whose presence is believed to facilitate the structural transition between amorphous and body centered cubic. (C) 2015 AIP Publishing LLC.
Return to Publications page