Quantum-mechanical study of the impact of thermal vibrations on
the stability of the FeSn2 intermetallics

a 2024

Quantum-mechanical study of the impact of thermal vibrations on the stability of the FeSn2 intermetallics

FRIÁK, Martin; Petr ČÍPEK; Pavla ROUPCOVÁ; Oldřich SCHNEEWEISS; Jana PAVLŮ et. al.

Základní údaje

Originální název

Quantum-mechanical study of the impact of thermal vibrations on the stability of the FeSn2 intermetallics

Autoři

FRIÁK, Martin (203 Česká republika, garant); Petr ČÍPEK (203 Česká republika, domácí); Pavla ROUPCOVÁ; Oldřich SCHNEEWEISS (203 Česká republika); Jana PAVLŮ (203 Česká republika, domácí); Dominika FINK; šárka MSALLAMOVÁ a Alena MICHALCOVÁ

Vydání

NANOCON, 2024

Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Obor

10403 Physical chemistry

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Kód RIV

RIV/00216224:14310/24:00139101

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

FeSn2; mechanical and thermodynamic stability; theoretical and experimental study

Změněno: 17. 3. 2025 19:37, doc. Mgr. Jana Pavlů, Ph.D.

Anotace

V originále

We have performed a combined theoretical and experimental study of FeSn2 intermetallics. We were motivated by a scarcity of published data as well as previous theoretical calculations of the antiferromagnetic (AFM) state of FeSn2, when this compound was found mechanically unstable due to imaginary-frequency phonons, i.e., effectively denying the existence of FeSn2. Addressing both mechanical and thermodynamic stability within density-functional theory (DFT) calculations, we focused on the AFM state as well as the ferromagnetic (FM) state of FeSn2, which were both considered in earlier experiments. In contrast to the previous calculations, we found the AFM FeSn2 state mechanically stable (no imaginary-frequency phonons). The same is true for the FM state, which possesses a slightly higher energy than the AFM state. The mechanical stability allowed for assessing the thermodynamic properties within both harmonic approximations as well as computationally much more demanding quasi-harmonic approximation. Interestingly, while the static-lattice formation energy of AFM FeSn2 is negative and, therefore, the compound is predicted stable with respect to the decomposition into elemental end-members, phonon-related contributions have a destabilizing impact at low temperatures. Our calculations were complemented by experimental characterization of Fe-Sn samples and the experimental FeSn2 lattice parameters were found in excellent agreement with theoretical values.

Návaznosti

LM2018140, projekt VaV

Název: e-Infrastruktura CZ (Akronym: e-INFRA CZ)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, e-Infrastruktura CZ

90254, velká výzkumná infrastruktura

Název: e-INFRA CZ II

Citovat

FRIÁK, Martin; Petr ČÍPEK; Pavla ROUPCOVÁ; Oldřich SCHNEEWEISS; Jana PAVLŮ; Dominika FINK; šárka MSALLAMOVÁ a Alena MICHALCOVÁ. Quantum-mechanical study of the impact of thermal vibrations on the stability of the FeSn2 intermetallics. In NANOCON. 2024.

@proceedings{2484893,
   author = {Friák, Martin and Čípek, Petr and Roupcová, Pavla and Schneeweiss, Oldřich and Pavlů, Jana and Fink, Dominika and Msallamová, šárka and Michalcová, Alena},
   booktitle = {NANOCON},
   keywords = {FeSn2; mechanical and thermodynamic stability; theoretical and experimental study},
   language = {eng},
   title = {Quantum-mechanical study of the impact of thermal vibrations on the stability of the FeSn2 intermetallics},
   year = {2024}
}

TY  - CONF
ID  - 2484893
AU  - Friák, Martin - Čípek, Petr - Roupcová, Pavla - Schneeweiss, Oldřich - Pavlů, Jana - Fink, Dominika - Msallamová, šárka - Michalcová, Alena
PY  - 2024
TI  - Quantum-mechanical study of the impact of thermal vibrations on the stability of the FeSn2 intermetallics
KW  - FeSn2
KW  - mechanical and thermodynamic stability
KW  - theoretical and experimental study
N2  - We have performed a combined theoretical and experimental study of FeSn2 intermetallics. We were motivated by a scarcity of published data as well as previous theoretical calculations of the antiferromagnetic (AFM) state of FeSn2, when this compound was found mechanically unstable due to imaginary-frequency phonons, i.e., effectively denying the existence of FeSn2. Addressing both mechanical and thermodynamic stability within density-functional theory (DFT) calculations, we focused on the AFM state as well as the ferromagnetic (FM) state of FeSn2, which were both considered in earlier experiments. In contrast to the previous calculations, we found the AFM FeSn2 state mechanically stable (no imaginary-frequency phonons). The same is true for the FM state, which possesses a slightly higher energy than the AFM state. The mechanical stability allowed for assessing the thermodynamic properties within both harmonic approximations as well as computationally much more demanding quasi-harmonic approximation. Interestingly, while the static-lattice formation energy of AFM FeSn2 is negative and, therefore, the compound is predicted stable with respect to the decomposition into elemental end-members, phonon-related contributions have a destabilizing impact at low temperatures. Our calculations were complemented by experimental characterization of Fe-Sn samples and the experimental FeSn2 lattice parameters were found in excellent agreement with theoretical values.
ER  -

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