Publication detail

Materials properties of defect-stabilized off-stoichiometric z-phase Al 2 Ge2 Mg

FRIÁK, M. ZOBAČ, O. CHLUP, Z. FIKAR, O. PAPEŽ, P. ZELENÝ, M. KROUPA, A.

Original Title

Materials properties of defect-stabilized off-stoichiometric z-phase Al 2 Ge2 Mg

Type

journal article in Web of Science

Language

English

Original Abstract

We have performed a quantum-mechanical study of off-stoichiometric Al 2 Ge 2 Mg z-phase intermetallic compounds. Our calculations focused on evaluating the formation energy of static lattices, their elastic properties as well as free energy of formation including phonon contributions. While the stoichiometric Al 2 Ge 2 Mg z phase was found thermodynamically, mechanically and dynamically stable, we have identified an off-stoichiometric composition Al 7 Ge 8 Mg 5 which exhibits the free energy of formation lower than the stoichiometric compound. The Al 7 Ge 8 Mg 5 was found both mechanically and dynamically stable as well. This off-stoichiometric compound has Mg atoms located also at the Al sublattice, i.e. these defects exhibit a stabilizing effect. Phonon contributions into the free energy of formation have turned out to be crucial for a proper description of the thermodynamic stability. In contrast, several other off-stoichiometric states are significantly thermodynamically destabilized by anti-site atoms at the Ge sublattice. The formation energy and the homogenized polycrystal Young ' s modulus are found anti-correlated indicating a connection between the thermodynamic and mechanical stability. Regarding the theoretical values of homogenized polycrystal Young ' s moduli, our measurements resulted in values quite close to the predicted ones.

Keywords

Al-Ge-Mg; Defects; Stability; Elasticity; Ab initio; Phonons PACS; 31.15.es; 61.72.-y; 64.70.kd; 63.20.-e; 81.40.Jj

Authors

FRIÁK, M.; ZOBAČ, O.; CHLUP, Z.; FIKAR, O.; PAPEŽ, P.; ZELENÝ, M.; KROUPA, A.

Released

1. 6. 2024

Publisher

ELSEVIER SCI LTD

Location

London

ISBN

0966-9795

Periodical

INTERMETALLICS

Year of study

169

Number

-

State

United Kingdom of Great Britain and Northern Ireland

Pages from

108294

Pages to

-

Pages count

10

URL

https://www.sciencedirect.com/science/article/abs/pii/S0966979524001134

BibTex

@article{BUT188811,
  author="Martin {Friák} and Ondřej {Zobač} and Zdeněk {Chlup} and Ondřej {Fikar} and Pavel {Papež} and Martin {Zelený} and Aleš {Kroupa}",
  title="Materials properties of defect-stabilized off-stoichiometric z-phase Al 2 Ge2 Mg",
  journal="INTERMETALLICS",
  year="2024",
  volume="169",
  number="-",
  pages="10",
  doi="10.1016/j.intermet.2024.108294",
  issn="0966-9795",
  url="https://www.sciencedirect.com/science/article/abs/pii/S0966979524001134"
}