Short- and medium-range orders in Al-Mn melts

• Published in: Russian metallurgy Metally Vol. 2009; no. 3; pp. 201 - 207
• Main Authors: Roik, A. S., Galushko, S. N., Samsonnikov, A. V., Kazimirov, V. P., Sokol’skii, V. E., Shovskii, V. A.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-06-2009; Springer Nature B.V
• Subjects: Aluminum; Chemistry and Materials Science; Computer simulation; Diffraction; Manganese; Materials Science; Mathematical models; Melts; Metallic Materials; Monte Carlo methods; Monte Carlo simulation; Polyhedrons; Studies; 81.30.Fb
• ISSN: 0036-0295; 1555-6255; 1531-8648
• DOI: 10.1134/S0036029509030033

The structures of Al-Mn melts with 14.3, 20, 26.7, 40, 50, and 70 at % Mn are studied by X-ray diffraction at a temperature 50°C above the liquidus temperature. The reverse Monte Carlo simulation and experimental structure-factor curves are used to construct structural models for liquid Al, Mn, and their binary melts. The character of atomic ordering on short- and medium-range scales is studied by dividing model configurations into Voronoi polyhedra and Delaunay simplexes. A nonmonotonic dependence of structural parameters is found in the region with a high aluminum content. The structural parameters have extremum values in an Al
6
Mn melt. The prepeak in the structure-factor curves in the diffraction vector range 9–25 nm
−1
is shown to be caused by a chemical atomic order in polytetrahedral clusters.