Effect of Cr-doping on the electronic structure and work function of α-Fe2O3 thin films

文献情報

出版日 2017-09-05

DOI 10.1039/C7CP02472J

インパクトファクター 3.676

著者

Li Chen, Hongmei Liu, Zhishan Mi, Changmin Shi, Lijie Qiao

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要旨

We investigate the effect of Cr-doping on the properties of α-Fe2O3(001) thin films with Fe termination using the local density approximation plus a Hubbard U correction. We find that both the doping site and concentration of Cr atoms dramatically affect the electronic structure and work function (WF) of α-Fe2O3 films. The results demonstrate that it is most energetically favorable for Cr atoms to substitute the Fe atoms in the sub-surface of α-Fe2O3 thin films. The doping of Cr atoms in the sub-surface not only lowers the band gap of the film but also greatly enhances the work function by 0.9 eV with respect to the pure α-Fe2O3 film. The increase of WF correlates with the reduction of occupied O px/py states at the top valence band which leads to a decrease of the Fermi energy. As the Cr concentration changes from 4.2% to 16.7%, the WF firstly increases, and then drops. The WF reaches a maximum of 6.61 eV for the Cr concentration of 8.3%. These results suggest that doping Cr atoms in a α-Fe2O3(001) thin film can increase the corrosion potential and benefits the protection of steel from corrosion.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

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