%0 Journal Article
%A Tober, Steffen
%A Schober, Jan-Christian
%A Creutzburg, Marcus
%A Beck, Esko Erik
%A Semione, Guilherme Dalla Lana
%A Chung, Simon
%A Jacobse, Leon
%A Arndt, Bjoern
%A Vlad, Alina
%A Steinbrügge, René
%A Wille, Hans-Christian
%A Sergeev, Ilya
%A Noei, Heshmat
%A Schlage, Kai
%A Leupold, Olaf
%A Vonk, Vedran
%A Stierle, Andreas
%T Site-Resolved Near-Surface Cation Diffusion in Magnetite
%J Physical review letters
%V 134
%N 23
%@ 0031-9007
%C College Park, Md.
%I APS
%M PUBDB-2025-01918
%P 236203
%D 2025
%X In situ nuclear forward scattering shows a thermally induced cation exchange between a 57 Fe3 ⁢O4 thin-film and a Fe3⁢ O4 (001) substrate predominantly in the octahedral sublattice for a temperature range between 470 and 710 K. The overall activation barrier in this temperature range is found to be 19±32  kJ/mol, which is significantly lower than expected from extrapolating a bulk diffusion model. This observation can be attributed to the large out-of-equilibrium cation deficit as determined by surface x-ray diffraction. Despite the relatively low hopping barrier, the diffusion constant is about 5 orders of magnitude lower than expected for magnetite having an equilibrium cation stoichiometry. The results are relevant for applications relying on the near-surface structure and stoichiometry of magnetite, and we argue that the correlation between cation diffusion and stoichiometry may play a role for a wider range of oxide materials.
%F PUB:(DE-HGF)16
%9 Journal Article
%R 10.1103/PhysRevLett.134.236203
%U https://bib-pubdb1.desy.de/record/631049