Surface metal-insulator transition on a vanadium pentoxide (001) single crystal.
In situ band gap mapping of the V2O5(001) crystal surface revealed a reversible metal-to-insulator transition at 350-400 K, which occurs inhomogeneously across the surface and expands preferentially in the direction of the vanadyl (V=O) double rows. Supported by density functional theory and Monte Carlo simulations, the results are rationalized on the basis of the anisotropic growth of vanadyl-oxygen vacancies and a concomitant oxygen loss driven metal-to-insulator transition at the surface. At elevated temperatures irreversible surface reduction proceeds sequentially as V2O5(001) --> V6O13(001) --> V2O3(0001).
Blum
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RP
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, Berlin 14195, Germany.
Niehus
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H
Hucho
C
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Fortrie
R
R
Ganduglia-Pirovano
M V
MV
Sauer
J
J
Shaikhutdinov
S
S
Freund
H-J
HJ