Structural behavior of Tantalum monatomic metallic glass

• Published in: Journal of non-crystalline solids 2019-04, Vol.510, p.81-92
• Main Authors: Khmich, A., Sbiaai, K., Hasnaoui, A.
• Format: Article
• Language: English
• Subjects: Fractal dimension; Icosahedral clusters; Molecular dynamics; Monatomic metallic glass; Voronoi tessellation
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2019.01.024

We simulated the Tantalum (Ta) system to form monatomic metallic glass (MG), using molecular dynamics (MD). The simulation is investigated within the framework of the embedded atom method (EAM) potential. Owing to studying the local atomic structure of Ta monoatomic MG, several structural analysis techniques are adopted to characterize the polyhedral network in terms of short-range order (SRO) and medium-range order (MRO). The simulation results confirm that the splitting in the second peak of the radial distribution function (RDF) proving the formation of amorphous phase. We found that the distorted Voronoi icosahedra is the most dominant polyhedral cluster in the formed Ta monatomic MG. From another side, in terms of MRO, the icosahedral clusters are found to be connected via intercross-sharing (IS), face-sharing (FS), edge-sharing (ES) and vertex-sharing (VS). We have also found that the five-fold symmetry governs the formation of the amorphous state and may behaves as a principal indication of the formation of the glassy state during the cooling process. The ratio Ri/R1 of RDF obtained showed the presence of a hidden crystalline order in Ta monatomic MG, which can be interpreted by a combination between spherical- periodic order (SPO) and local translational symmetry (LTS). Furthermore, the atomic-level analysis of the structure revealed that the glass has a fractal dimension (Df = 2.59) between the center atom and the first coordination shell, while beyond the first coordination shell Df = 3.01, which suggests the development of fractal dimension at short distance. •Distorted icosahedra is the most dominant polyhedra in Ta monatomic MG;•Five-fold symmetry may mark the MG formation;•A hidden crystalline order is detected during the formation of Ta monatomic MG;•Ta monatomic metallic glass presents a fractal dimension.