Počet záznamů: 1  

Quantum-Mechanical Study of Nanocomposites with\nLow and Ultra-Low Interface Energies

  1. 1.
    0498985 - ÚFM 2019 RIV CH eng J - Článek v odborném periodiku
    Friák, Martin - Holec, D. - Šob, Mojmír
    Quantum-Mechanical Study of Nanocomposites with
    Low and Ultra-Low Interface Energies.
    Nanomaterials. Roč. 8, č. 12 (2018), č. článku 1057. E-ISSN 2079-4991
    Grant CEP: GA ČR(CZ) GA16-24711S; GA ČR(CZ) GA17-22139S
    Institucionální podpora: RVO:68081723
    Klíčová slova: MoSi2 * WSi2 * TaSi2 * NbSi2 * elasticity * ab initio * interface energies * Fe3Al * disorder
    Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
    Impakt faktor: 4.034, rok: 2018

    We applied first-principles electronic structure calculations to study structural,
    thermodynamic and elastic properties of nanocomposites exhibiting nearly perfect match of
    constituting phases. In particular, two combinations of transition-metal disilicides and one pair
    of magnetic phases containing the Fe and Al atoms with different atomic ordering were considered.
    Regarding the disilicides, nanocomposites MoSi2/WSi2 with constituents crystallizing in the
    tetragonal C11b structure and TaSi2/NbSi2 with individual phases crystallizing in the hexagonal
    C40 structure were simulated. Constituents within each pair of materials exhibit very similar
    structural and elastic properties and for their nanocomposites we obtained ultra-low (nearly zero)
    interface energy (within the error bar of our calculations, i.e., about 0.005 J/m2). The interface
    energy was found to be nearly independent on the width of individual constituents within the
    nanocomposites and/or crystallographic orientation of the interfaces. As far as the nanocomposites
    containing Fe and Al were concerned, we simulated coherent superlattices formed by an ordered
    Fe3Al intermetallic compound and a disordered Fe-Al phase with 18.75 at.% Al, the a-phase. Both
    phases were structurally and elastically quite similar but the disordered a-phase lacked a long-range
    periodicity. To determine the interface energy in these nanocomposites, we simulated seven different
    distributions of atoms in the a-phase interfacing the Fe3Al intermetallic compound. The resulting
    interface energies ranged from ultra low to low values, i.e., from 0.005 to 0.139 J/m2. The impact of
    atomic distribution on the elastic properties was found insignificant but local magnetic moments of
    the iron atoms depend sensitively on the type and distribution of surrounding atoms.
    Trvalý link: http://hdl.handle.net/11104/0293614

     
     
Počet záznamů: 1  

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