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Název:
Theoretical modelling of phase stability, magnetic and mechanical properties of compounds based on transition metals
Překlad názvu: Theoretical modelling of phase stability, magnetic and mechanical properties of compounds based on transition metals
Autoři: Heczko, Martin ; Friák, Martin (oponent) ; Veis, Martin (oponent) ; Zelený, Martin (vedoucí práce)
Typ dokumentu: Disertační práce
Rok: 2025
Jazyk: eng
Nakladatel: Vysoké učení technické v Brně. Fakulta strojního inženýrství
Abstrakt: In this Doctoral thesis, ab initio calculations of electronic structure within the projector augmented wave method are employed to study physical properties of several compounds containing transition metals and manifesting magnetic ordering. In particular, three material problems were studied, namely the magnetic properties of complex A2BBO6 oxides in dependence of various A, B and B metallic elements; the mechanism twinning on atomic level and its application on NM martensite of Mn-rich Ni-Mn-Ga alloys and the phase transformation and stability in Fe2C. The results of first part show that to achieve the highest Curie temperature in A2BBO6 oxides, A element must have ionic radius as small as possible while the magnetic moments of B and B must be maximized. For deformation twinning of Ni-Mn-Ga alloys it is demonstrated that Mn excess leads to more difficult twinning due to increased phase stability of non-modulated martensite and magnetic ordering of excess Mn atoms. At last but not least, the formation of orthorhombic Fe2C from tetragonal rutile structure is explained from thermodynamical, mechanical and kinetic perspectives as a stabilization due to pseudo-Jahn-Teller effect.
Klíčová slova: Ab initio methods; ferromagnetic shape memory alloys; multiferroic oxides; phase stability; twinning; Ab initio methods; ferromagnetic shape memory alloys; multiferroic oxides; phase stability; twinning
Instituce: Vysoké učení technické v Brně (web)
Informace o dostupnosti dokumentu: Plný text je dostupný v Digitální knihovně VUT.
Původní záznam: https://hdl.handle.net/11012/250894
Trvalý odkaz NUŠL: http://www.nusl.cz/ntk/nusl-678850
Překlad názvu: Theoretical modelling of phase stability, magnetic and mechanical properties of compounds based on transition metals
Autoři: Heczko, Martin ; Friák, Martin (oponent) ; Veis, Martin (oponent) ; Zelený, Martin (vedoucí práce)
Typ dokumentu: Disertační práce
Rok: 2025
Jazyk: eng
Nakladatel: Vysoké učení technické v Brně. Fakulta strojního inženýrství
Abstrakt: In this Doctoral thesis, ab initio calculations of electronic structure within the projector augmented wave method are employed to study physical properties of several compounds containing transition metals and manifesting magnetic ordering. In particular, three material problems were studied, namely the magnetic properties of complex A2BBO6 oxides in dependence of various A, B and B metallic elements; the mechanism twinning on atomic level and its application on NM martensite of Mn-rich Ni-Mn-Ga alloys and the phase transformation and stability in Fe2C. The results of first part show that to achieve the highest Curie temperature in A2BBO6 oxides, A element must have ionic radius as small as possible while the magnetic moments of B and B must be maximized. For deformation twinning of Ni-Mn-Ga alloys it is demonstrated that Mn excess leads to more difficult twinning due to increased phase stability of non-modulated martensite and magnetic ordering of excess Mn atoms. At last but not least, the formation of orthorhombic Fe2C from tetragonal rutile structure is explained from thermodynamical, mechanical and kinetic perspectives as a stabilization due to pseudo-Jahn-Teller effect.
Klíčová slova: Ab initio methods; ferromagnetic shape memory alloys; multiferroic oxides; phase stability; twinning; Ab initio methods; ferromagnetic shape memory alloys; multiferroic oxides; phase stability; twinning
Instituce: Vysoké učení technické v Brně (web)
Informace o dostupnosti dokumentu: Plný text je dostupný v Digitální knihovně VUT.
Původní záznam: https://hdl.handle.net/11012/250894
Trvalý odkaz NUŠL: http://www.nusl.cz/ntk/nusl-678850
Záznam vytvořen dne 2025-05-03, naposledy upraven 2025-05-03.