Materials (Jan 2022)

Effect of Twinning on Angle-Resolved Photoemission Spectroscopy Analysis of Ni<sub>49.7</sub>Mn<sub>29.1</sub>Ga<sub>21.2</sub>(100) Heusler Alloy

  • Vladimír Cháb,
  • Václav Drchal,
  • František Máca,
  • Josef Kudrnovský,
  • Stanislav Cichoň,
  • Ján Lančok,
  • Oleg Heczko

DOI
https://doi.org/10.3390/ma15030717
Journal volume & issue
Vol. 15, no. 3
p. 717

Abstract

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To explain the observed features of k-space photoelectron images taken on off-stoichiometric Heusler Ni49.7Mn29.1Ga21.2 single-crystals in the cubic austenitic and pseudotetragonal martensitic phases, the images were simulated theoretically. Despite the moderate structural difference of both phases, there is large difference in photoemission spectra. Analysis of the final states’ structure, matrix elements, and interface barrier scattering was performed to interpret discrepancies between the external photoemission of the austenite and martensite. The missing signal at the surface-normal emission of the martensitic phase is, ultimately, explained by repeated scatterings of escaping electrons on the interfaces between nanotwins.

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