Název: Quantum-mechanical study of magnetic properties of superalloy nanocomposite phase Fe2AlTi
Autoři: Slávik, Anton ; Miháliková, Ivana ; Friák, Martin ; Všianská, Monika ; Šob, Mojmír
Typ dokumentu: Příspěvky z konference
Konference/Akce: NANOCON 2017. International Conference on Nanomaterials - Research & Application /9./, Brno (CZ), 20171018
Rok: 2018
Jazyk: eng
Abstrakt: 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.
Klíčová slova: Ab initio calculations; Fe-Al based superalloys; Fixed-spin-moment; Nanocomposites
Číslo projektu: LM2015069 (CEP), GA17-22139S (CEP), GA16-24711S (CEP)
Poskytovatel projektu: GA MŠk, GA ČR, GA ČR
Zdrojový dokument: NANOCON 2017: Conference Proceedings, ISBN 978-80-87294-81-9

Instituce: Ústav fyziky materiálů AV ČR (web)
Informace o dostupnosti dokumentu: Dokument je dostupný v příslušném ústavu Akademie věd ČR.
Původní záznam: http://hdl.handle.net/11104/0289458

Trvalý odkaz NUŠL: http://www.nusl.cz/ntk/nusl-391445


Záznam je zařazen do těchto sbírek:
Věda a výzkum > AV ČR > Ústav fyziky materiálů
Konferenční materiály > Příspěvky z konference