TY  - JOUR
AU  - Tober, Steffen
AU  - Schober, Jan-Christian
AU  - Creutzburg, Marcus
AU  - Beck, Esko Erik
AU  - Semione, Guilherme Dalla Lana
AU  - Chung, Simon
AU  - Jacobse, Leon
AU  - Arndt, Bjoern
AU  - Vlad, Alina
AU  - Steinbrügge, René
AU  - Wille, Hans-Christian
AU  - Sergeev, Ilya
AU  - Noei, Heshmat
AU  - Schlage, Kai
AU  - Leupold, Olaf
AU  - Vonk, Vedran
AU  - Stierle, Andreas
TI  - Site-Resolved Near-Surface Cation Diffusion in Magnetite
JO  - Physical review letters
VL  - 134
IS  - 23
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - PUBDB-2025-01918
SP  - 236203
PY  - 2025
AB  - 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.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1103/PhysRevLett.134.236203
UR  - https://bib-pubdb1.desy.de/record/631049
ER  -