Origin of the absent (2×2) reconstruction on Fe3GeTe2

Determine why the (2×2) surface reconstruction appears on the surfaces of epitaxial α-MnTe(0001) films grown on the studied substrates, except for films grown on Fe3GeTe2(0001), despite post-growth annealing and tellurium deposition.

Background

The paper reports a (2×2) surface reconstruction on all examined α-MnTe(0001) films except those grown on the van der Waals ferromagnet Fe3GeTe2. Neither tellurium deposition nor post-growth annealing produces this reconstruction in the MnTe/Fe3GeTe2 system. The authors suggest that the difference may result from the improved surface morphology and larger terraces of MnTe grown on Fe3GeTe2, which could facilitate tellurium diffusion and healing of surface vacancies, but they do not establish the cause. They propose quantitative LEED-I(V) structure analysis as a means of clarifying the discrepancy.

References

It remains unsolved why we observe the $(2\times 2)$ superstructure on the surface of all grown $\alpha$-MnTe(0001) films except for the _3 case. Neither post-growth annealing nor Te deposition led to the formation of a $(2\times 2)$ reconstruction in the MnTe\, /\, _3 system.

— Growth of Altermagnetic α-MnTe Films: Substrate Variation and Surface Modification  (2608.17513 - Dittmar et al., 18 Aug 2026) in Section 3.2, subsection “Surface superstructures”