Original title: Vliv segregovaných nemagnetických sp-nečistot na vlastnosti hranic zrn a povrchů v niklu
Translated title: Effect of segregated nonmagnetic sp-impurities on the properties of grain boundaries and surfaces in nickel
Authors: Všianská, Monika ; Šob, Mojmír
Document type: Papers
Conference/Event: Víceúrovňový design pokrokových materiálů, Brno (CZ), 2011-12-01 / 2011-12-02
Year: 2011
Language: cze
Abstract: [cze] [eng]
V práci jsme studovali segregaci 12 nemagnetických sp-nečistot (Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te) na hranici zrn Sigma5(210) a na povrchu (210) ve feromagnetickém niklu a analyzujeme jejich vliv na strukturu a magnetické a mechanické vlastnosti. Určili jsme preferenční místa segregace atomů nečistot a vypočetli jsme jejich segregační entalpie a zkřehčovací energie včetně rozkladu na mechanickou a chemickou komponentu. Ukázali jsme, že magneticky mrtvé vrstvy na hranicích zrn a površích se segregovanými nečistotami jsou způsobené silnou hybridizací sp-stavů nečistot a d-stavů niklu. We present an ab initio study of segregation of 12 nonmagnetic sp impurities (Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te) at the Sigma5(210) grain boundary (GB) and (210) free surface (FS) in fcc ferromagnetic nickel and analyze their effect on structure, magnetic and mechanical properties. We determine the preferred segregation sites of the impurity atoms, their segregation enthalpies and strengthening/embrittling energies with their decomposition into the chemical and mechanical components. We find that the value of mechanical component is dependent on the type of the stable segregation position and is nearly constant in each period. On the other hand the chemical component changes strongly within each period and is determined by the electronegativity of impurity atoms. Magnetically dead layers found at the impurity segregated GB and FS are caused by a strong hybridization of sp states of the impurities with the d states of nickel.
Keywords: grain boundary; nickel; segregation
Project no.: CEZ:AV0Z20410507 (CEP), IAA100100920 (CEP), GD106/09/H035 (CEP)
Funding provider: GA AV ČR, GA ČR
Host item entry: Víceúrovňový design pokrokových materiálů: sborník doktorské konference 2011, ISBN 978-80-87434-04-8

Institution: Institute of Physics of Materials AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0205152

Permalink: http://www.nusl.cz/ntk/nusl-81281


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Research > Institutes ASCR > Institute of Physics of Materials
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