Original title: Quantum-mechanical study of magnetic properties of superalloy nanocomposite phase Fe2AlTi
Authors: Slávik, Anton ; Miháliková, Ivana ; Friák, Martin ; Všianská, Monika ; Šob, Mojmír
Document type: Papers
Conference/Event: NANOCON 2017. International Conference on Nanomaterials - Research & Application /9./, Brno (CZ), 20171018
Year: 2018
Language: eng
Abstract: The L21-structure Fe2AlTi intermetallic compound is one of the two phases identified in Fe-Al-Ti superalloy nanocomposites. Experimental data related to low-temperature magnetic properties of this Heusler compound indicate that magnetic moment is about 0.1 Bohr magneton per formula unit. In contrast, previous quantum-mechanical calculations predicted Fe2AlTi to have much higher magnetic moment, 0.9 Bohr magneton per formula unit. In order to solve this discrepancy between the theory and experiment we have performed a series of quantum-mechanical fix-spin-moment calculations and compared our results with those for non-magnetic state. It turns out that the total energy of the non-magnetic state is only by 10.73 meV/atom higher than that of the magnetic state. When applying Boltzmann statistics to this very small energy difference we predict that the non-magnetic state appears at non-zero temperatures with significant probabilities (for instance, 22.36 % at T = 100 K) and reduces the overall magnetic moment. As another mechanism lowering the magnetization we studied selected shape deformations, in particular trigonal shearing. Fe2AlTi exhibits a compression-tension asymmetry with respect to these strains and, for example, the strain 0.08 destabilizes the spin-polarized state, leaving the non-magnetic state as the only stable one.
Keywords: Ab initio calculations; Fe-Al based superalloys; Fixed-spin-moment; Nanocomposites
Project no.: LM2015069 (CEP), GA17-22139S (CEP), GA16-24711S (CEP)
Funding provider: GA MŠk, GA ČR, GA ČR
Host item entry: NANOCON 2017: Conference Proceedings, ISBN 978-80-87294-81-9

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/11104/0289458

Permalink: http://www.nusl.cz/ntk/nusl-391445

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Research > Institutes ASCR > Institute of Physics of Materials
Conference materials > Papers
 Record created 2019-02-13, last modified 2020-03-27

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