Why the case for clean surfaces does not hold water: Structure and morphology of hydroxylated nickel oxide (111)

作者：Ciston J^*; Subramanian A; Kienzle D M; Marks L D

来源：Surface Science, 2010, 604(2): 155-164.

DOI：10.1016/j.susc.2009.10.033

• Nickel oxide
• Transmission high-energy electron diffraction
• Density functional calculations
• Surface structure kinetics
• Hydroxylation

We report an experimental and theoretical analysis of the root 3 x root 3-R30 degrees and 2 x 2 reconstructions on the NiO (1 1 1) surface combining transmission electron microscopy, X-ray photoelectron spectroscopy, and reasonably accurate density functional calculations using the meta-GGA hybrid functional TPSSh. While the main focus here is on the surface structure, we also observe an unusual step morphology with terraces containing only even numbers of unit cells during annealing of the surfaces. The experimental data clearly shows that the surfaces contain significant coverage of hydroxyl terminations, and the surface structures are essentially the same as those reported on the MgO (1 1 1) surface implying an identical kinetically-limited water-driven structural transition pathway. The octapole structure can therefore be all but ruled out for single crystals of NiO annealed in or transported through humid air. The theoretical analysis indicates, as expected, that simple density functional theory methods for such strongly-correlated oxide surfaces are marginal, while better consideration of the metal cl-electrons has a large effect although it is still not perfect.

• 出版日期2010-1-15
• 单位西北大学