Impact of extreme electrical fields on charge density distributions in Al3Sc alloy

Claudia Loyola, Joaquin Peralta, Scott R. Broderick, Krishna Rajan

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In this study, the authors investigated how extreme electrical fields affect charge distribution of metallic surfaces and bond character at the moment of evaporation. The surface structure and neighborhood chemistry were also studied as a function of various field evaporation pathways. Density functional theory (DFT) was used to model the surface bonding and charge distribution and then correlate the DFT results with experimental results by comparing the calculated evaporation fields with atom probe tomography measurements. The evaporation fields of different surface neighborhood chemistries in L12-Al3Sc were calculated, with the Sc atoms occupying the corners of a cubic unit cell and the Al atoms occupying the face centers. Al-Al surface atoms are found via DFT to be more likely to evaporate as dimers because of the Al-Al shared charge density. In contrast, Al-Sc evaporates as single ions due to the increased density localized around the Sc atom. This difference in evaporation behavior correlates with the resistance to degradation under extreme fields. This work allows better interpretation of the atom probe data by clarifying the relationship between different evaporation events and the role of surface and subsurface chemistry.

Original languageEnglish
Article number061404
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Volume34
Issue number6
DOIs
Publication statusPublished - 1 Nov 2016

Fingerprint

Charge density
density distribution
Evaporation
evaporation
Atoms
Density functional theory
atoms
Charge distribution
chemistry
density functional theory
charge distribution
probes
Surface chemistry
Surface structure
Dimers
Tomography
tomography
dimers
Ions
degradation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

Cite this

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Impact of extreme electrical fields on charge density distributions in Al3Sc alloy. / Loyola, Claudia; Peralta, Joaquin; Broderick, Scott R.; Rajan, Krishna.

In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, Vol. 34, No. 6, 061404, 01.11.2016.

Research output: Contribution to journalArticle

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