Ordering and diffusion in liquid magnesium antimonide (Mg3Sb2) from hypernetted-chain theory and molecular dynamics simulation

• Published in: Ionics 2019-06, Vol.25 (6), p.2711-2717
• Main Authors: Akdere, Ünsal, Günay, Seçkin D., Taşseven, Çetin
• Format: Article
• Language: English
• Subjects: Antimony; Chains; Chemistry; Chemistry and Materials Science; Clusters; Condensed Matter Physics; Electrochemistry; Energy Storage; Ion diffusion; Magnesium; Melts; Molecular chains; Molecular dynamics; Molecular structure; Optical and Electronic Materials; Original Paper; Renewable and Green Energy; Structure factor
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-018-2757-2

The static structure and ionic transport in molten Mg 3 Sb 2 was investigated by means of the hypernetted-chain theory of liquids (HNC) and the molecular dynamics simulation (MD) using a semi-empirical pairwise potential together with the liquid-state density that was estimated from the procedure of finding minimum energy. Magnesium sublattice melts into a more disordered liquid state with a higher mobility compared to antimony. Highly mobile magnesium ions indicate the cluster distribution over a range. Tendency of the pre-peak at low k region ( k  ≅ 1.7 Å -1 ) in the pair structure factor S NN ( k ) may be the result of the one of the n-fold Voronoi coordination polyhedral clusters that dominates over the other clusters. The results also suggest that the pair structure factor of the less mobile ion influences the low-  k peak in S NN ( k ) that might be a characteristic feature of the systems whose components have markedly different self-ionic diffusion.