Publication detail

QUANTUM-MECHANICAL STUDY OF INTERNAL STRUCTURAL TRANSFORMATIONS IN Pb-SUPERSATURATED Pb-Sn ALLOYS

FRIÁK, M. ČÍPEK, P. PAVLŮ, J. ROUPCOVÁ, P. MIHÁLIKOVÁ, I. MSALLAMOVÁ, Š. MICHALCOVÁ, A.

Original Title

QUANTUM-MECHANICAL STUDY OF INTERNAL STRUCTURAL TRANSFORMATIONS IN Pb-SUPERSATURATED Pb-Sn ALLOYS

Type

conference paper

Language

English

Original Abstract

Motivated by a decades-long controversy related to the crystal structure of Pb-supersaturated solid solutions of Pb in Sn, we have performed a quantum-mechanical study of these materials. Focusing on both body-centred-tetragonal beta-Sn and simple-hexagonal gamma-Sn structures, we have computed properties of two alloys with the chemical composition Pb5Sn11, i.e. 31.25 at. % Pb, which is close to the composition of the experimentally found alloy (30 at. % Pb). The 16-atom computational supercells were designed as multiples of the elemental beta- and gamma-Sn unit cells, where the Pb atoms were distributed according to the special quasi-random structure (SQS) concept. Full structural relaxations of both beta- and gamma-phase-based alloys resulted in very significant re-arrangements into structures which do not exhibit any apparent structural features typical for the original alloys, and are, therefore, difficult to classify. The formation energies of the beta- and gamma-phase-originating equilibrium phases are 50 meV/atom and 53 meV/atom, respectively. Therefore, they are not stable with respect to the decomposition into the elemental lead and tin. Moreover, our calculations of elastic constants of both phases revealed that they are close to mechanical instability. Our results indicate that the studied Pb-supersaturated Pb-Sn solid solutions may be prone to structural instability, transformations into different phases and decomposition. Our findings may contribute into the identification of the reason why the subsequent experimental studies did not reproduce the initial published data.

Keywords

Pb-Sn alloys; stability; supersaturation; quantum-mechanical calculations

Authors

FRIÁK, M.; ČÍPEK, P.; PAVLŮ, J.; ROUPCOVÁ, P.; MIHÁLIKOVÁ, I.; MSALLAMOVÁ, Š.; MICHALCOVÁ, A.

Released

18. 10. 2023

Publisher

TANGER LTD

Location

SLEZSKA

ISBN

978-80-8836-515-0

Book

NANOCON Conference Proceedings

Pages from

15

Pages to

21

Pages count

7

URL

https://www.confer.cz/nanocon/2023/4749-structure-property-relations-in-pb-supersaturated-sn-rich-pb-sn-alloys

BibTex

@inproceedings{BUT189941,
  author="Martin {Friák} and Petr {Čípek} and Jana {Pavlů} and Pavla {Roupcová} and Ivana {Miháliková} and Šárka {Msallamová} and Alena {Michalcová}",
  title="QUANTUM-MECHANICAL STUDY OF INTERNAL STRUCTURAL TRANSFORMATIONS IN Pb-SUPERSATURATED Pb-Sn ALLOYS",
  booktitle="NANOCON Conference Proceedings",
  year="2023",
  pages="15--21",
  publisher="TANGER LTD",
  address="SLEZSKA",
  doi="10.37904/nanocon.2023.4749",
  isbn="978-80-8836-515-0",
  url="https://www.confer.cz/nanocon/2023/4749-structure-property-relations-in-pb-supersaturated-sn-rich-pb-sn-alloys"
}