Jahn-Teller stabilization of a "polar" metal oxide surface: Fe3O4(001).
Using ab initio thermodynamics we compile a phase diagram for the surface of Fe3O4(001) as a function of temperature and oxygen pressures. A hitherto ignored polar termination with octahedral iron and oxygen forming a wavelike structure along the [110] direction is identified as the lowest energy configuration over a broad range of oxygen gas-phase conditions. This novel geometry is confirmed via x-ray diffraction analysis. The stabilization of the Fe3O4(001) surface goes together with dramatic changes in the electronic and magnetic properties, e.g., a half metal to metal transition.
Pentcheva
R
R
Department of Earth and Environmental Sciences, University of Munich, Theresienstrasse 41, 80333 Munich, Germany. pentcheva@lrz.uni-muenchen.de
Wendler
F
F
Meyerheim
H L
HL
Moritz
W
W
Jedrecy
N
N
Scheffler
M
M