Lodziana Zbigniew
Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Kraków, Poland.
Phys Rev Lett. 2007 Nov 16;99(20):206402. doi: 10.1103/PhysRevLett.99.206402. Epub 2007 Nov 13.
We report density functional studies of the (001) surface of magnetite that account for local Coulomb interactions. Iron cations in the surface layers exhibit charge and t2g orbital ordering that is coupled with the lattice strains. Orbital ordering is present for various surface stoichiometries and causes opening of the band gap Eg approximately 0.3 eV at the surface, such that the (001) surface of Fe3O4 remains insulating also in the high temperature cubic phase. The (radical 2 x radical 2)R45 degrees surface reconstruction is related to orbital ordering.
我们报告了考虑局部库仑相互作用的磁铁矿（001）表面的密度泛函研究。表面层中的铁阳离子表现出电荷和t2g轨道有序化，这与晶格应变相关联。对于各种表面化学计量比，轨道有序化都存在，并导致表面处带隙Eg约为0.3 eV的打开，使得Fe3O4的（001）表面在高温立方相中也保持绝缘。（√2×√2）R45°表面重构与轨道有序化有关。
