Crystallographic features of the ν phase in the Mn-Si binary alloy system

Kei Nakayama, Shouhei Yabu, Takashi Mizuno, Yasumasa Koyama

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    In the Mn-Si alloy system, there is the intermetallic-compound ν phase around Mn-18at.%Si. Its crystal structure called the ν structure has been reported to involve complex coordination polyhedra with coordination numbers (CN's) 12, 14, and others. To clarify whether one of these polyhedra can be identified as a structural unit or not in the ν structure, we have investigated the crystallographic features of the (R → R + ν) reaction in Mn-15at.%Si alloy samples by transmission electron microscopy. In Mn-15at.%Si samples obtained by cooling from the single R phase at a relatively fast cooling rate, metastable precipitates were found to be present in the R-structure matrix. Their notable feature is that each precipitate involves regions exhibiting characteristic electron diffraction patterns, which indicate the presence of metastable states, in addition to the initial amorphous and final ν states. Based on the careful analysis of these patterns, it was understood that the metastable states were directly associated with the formation of the ν structure, and that the formation started with the appearance of dodecagonal atomic columns. Because a dodecagonal column is characterized by a one-dimensional array of CN14 polyhedra, among the coordination polyhedra involved in the ν structure, a CN14 polyhedron can be identified as its structural unit.

    Original languageEnglish
    Title of host publicationAdvanced Materials Research
    PublisherTrans Tech Publications
    Pages525-530
    Number of pages6
    Volume922
    ISBN (Print)9783038350743
    DOIs
    Publication statusPublished - 2014
    Event8th International Conference on Processing and Manufacturing of Advanced Materials: Processing, Fabrication, Properties, Applications, THERMEC 2013 - Las Vegas, NV
    Duration: 2013 Dec 22013 Dec 6

    Publication series

    NameAdvanced Materials Research
    Volume922
    ISSN (Print)10226680

    Other

    Other8th International Conference on Processing and Manufacturing of Advanced Materials: Processing, Fabrication, Properties, Applications, THERMEC 2013
    CityLas Vegas, NV
    Period13/12/213/12/6

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    Keywords

    • Coordination polyhedra
    • Dodecagonal atomic column
    • Intermetallic compound
    • Mn-Si alloy system
    • Transmission electron microscopy

    ASJC Scopus subject areas

    • Engineering(all)

    Cite this

    Nakayama, K., Yabu, S., Mizuno, T., & Koyama, Y. (2014). Crystallographic features of the ν phase in the Mn-Si binary alloy system. In Advanced Materials Research (Vol. 922, pp. 525-530). (Advanced Materials Research; Vol. 922). Trans Tech Publications. https://doi.org/10.4028/www.scientific.net/AMR.922.525