2.1 Estudios de doctorado y postdoctorado

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https://hdl.handle.net/20.500.12390/329

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Examinando 2.1 Estudios de doctorado y postdoctorado por Tema "A1. Phase diagramsA2"
  • Publicación
    Forced convection by Inclined Rotary Bridgman method for growth of CoSb3 and FeSb2 single crystals from Sb-rich solutions
    (Elsevier B.V., 2017)
    Pillaca, M
    ;
    Harder, O
    ;
    Miller, W
    ;
    Gille, P
    Sb-based compounds such as CoSb3 and FeSb2 are interesting materials for thermoelectric applications. Their single crystal growth can be achieved from high-temperature solutions that are strongly enriched in Sb. In Bridgman growth using closed ampoules, effective mixing of the solution is an important prerequisite in order to minimize the high risk of liquid inclusion formation. We have successfully grown inclusion-free single crystal of CoSb3 and FeSb2 by rotating the ampoule in a Bridgman-type crystal growth set-up being inclined by 75° with respect to the vector of gravity. Numerical modelling as well as experimental growth studies have demonstrated the strong influence of forced convection that is achieved by this modified directional solidification technique called Inclined Rotary Bridgman method.
  • Publicación
    Single crystal growth of Ga3Ni2 by the Czochralski method
    (Elsevier B.V., 2016)
    Wencka, M
    ;
    Pillaca, M
    ;
    Gille, P
    Intermetallic compounds have proved to be interesting alternatives to heterogeneous catalysts prepared from pure noble metals or their alloys. As to study their intrinsic properties, to determine the crystalline structures of specific surfaces and finally to understand elementary processes of heterogeneous catalysis, single crystals of these intermetallics are needed. Inspired by the recent discovery of Ga–Ni catalysts for carbon dioxide reduction to methanol, we have grown for the first time cm3-size single crystals of trigonal Ga3Ni2. We report in detail on the synthesis and Czochralski growth from high-temperature solution using Ga as native solvent. Inclusion formation of Ga-rich fluid proved to be the most severe problem that was minimized by using an extremely low pulling rate down to 25µm/h.