Modifying vacancy defects during systematic disordering of the Cr2AlC nano-lamellar system

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • João S. Cabaço - , Helmholtz-Zentrum Dresden-Rossendorf, Technische Universität Dresden (Autor:in)
  • Maciej Oskar Liedke - , Helmholtz-Zentrum Dresden-Rossendorf (Autor:in)
  • Javier Pablo-Navarro - , University of Zaragoza (Autor:in)
  • Fabian Ganss - , Helmholtz-Zentrum Dresden-Rossendorf (Autor:in)
  • César Magén - , University of Zaragoza (Autor:in)
  • Manuel Ricardo Ibarra - , University of Zaragoza (Autor:in)
  • Ulrich Kentsch - , Helmholtz-Zentrum Dresden-Rossendorf (Autor:in)
  • Maik Butterling - , Helmholtz-Zentrum Dresden-Rossendorf (Autor:in)
  • Andreas Wagner - , Helmholtz-Zentrum Dresden-Rossendorf (Autor:in)
  • Jürgen Lindner - , Helmholtz-Zentrum Dresden-Rossendorf (Autor:in)
  • Jürgen Faßbender - , Professur für Angewandte Festkörperphysik (gB/HZDR), Helmholtz-Zentrum Dresden-Rossendorf, Technische Universität Dresden (Autor:in)
  • Christoph Leyens - , Professur für Werkstofftechnik, Technische Universität Dresden (Autor:in)
  • Richard Boucher - , Professur für Werkstofftechnik, Technische Universität Dresden (Autor:in)
  • Rantej Bali - , Helmholtz-Zentrum Dresden-Rossendorf (Autor:in)

Abstract

The layered structure of MAX phases is associated with a number of functional properties and is the subject of extensive research. While the unit-cell layers of these structures have been well studied, much less is known about the distribution and manipulation of point defects within them. Here, we selected the prototype Cr2AlC system and, using variable energy positron beams, observed Doppler broadening and positron annihilation lifetimes to track the evolution of defects caused by the penetration of energetic transition metal ions (Co+ and Mn+) and noble gas ions (Ar+ and Ne+). In all cases an overall reduction of the open-volume defect concentration is observed post-irradiation. Atomic displacements induced by the penetrating ions drastically modify the defect distribution: the concentration of agglomerates of 9–15 vacancies (corresponding to positron lifetimes of 335–450 ps) in the precursor [Cr2C/Al]n layers is suppressed, whereas Al mono- and Al-Cr di-vacancy (lifetimes 217–231 ps) concentrations are enhanced. This breakdown of large defects into point defects scales with atomic displacements and is largely independent of the penetrating ion species, providing insights into the manipulation of point defects in nano-layered systems.

Details

OriginalspracheEnglisch
Aufsatznummer161180
FachzeitschriftApplied surface science
Jahrgang679
PublikationsstatusVeröffentlicht - 15 Jan. 2025
Peer-Review-StatusJa

Schlagworte

Schlagwörter

  • CrAlC, Lattice defects, MAX phases, Positron annihilation spectroscopy, Vacancies