The structure of thin NiO(100) films grown on Ni(100) as determined by low-energy-electron diffraction and scanning tunneling microscopy

Oxidation of polycrystalline Ni studied by spectromicroscopy: Phase separation in the early stages of crystallite growth

“…NiO is the most common anti-ferromagnetic component in antiferromagnetic/ferromagnetic compound materials [3,4], where the film homogeneity is of extreme importance. The oxidation of Ni has, therefore, been studied over many years both on single crystal and polycrystalline samples [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. In order to describe the early stages a three-step mechanism has been proposed by Holloway and Hudson [9,10] for Ni{111} and {100}: the first step involves fast dissociative chemisorption of oxygen; secondly, NiO clusters nucleate and grow forming a thin NiO film; the last step involves slow thickening of the NiO film, which is limited by the diffusion of nickel cations through the oxide film [11].…”

“…A single metallic Ni 2p 3/2 photoemission peak of Ni{111} indicates that oxygen only chemisorbs for exposures up to 10 L (1 L = 10 −6 Torr·s) at room temperature, whereas for higher exposures additional XPS peaks indicate the formation of NiO [12,13]. STM images reveal that the oxide layer on Ni{111} and Ni{100} nucleates at step edges and grows into the terraces [14][15][16]. Chen et al [5,17] identified two distinct temperature regimes, below 500-600 K a 2-3 layers thick oxide film is formed, which wets and passivates the Ni surface; at higher temperatures the oxide film breaks up into three-dimensional crystallites.…”

Atomic Scale Characterization of Defects on Oxide Surfaces

“…Interestingly, the central spot arising from flat oxide regions is only detectable at certain energy conditions, demonstrating the impact of constructive and destructive interference of the electron beam between the two primary MgO/Mo registries. The MgO/Mo lattice mismatch therefore results in well-ordered domains with fixed tilt angles against the substrate plane, a phenomenon that is known as mosaicity [185,186]. The energetically favorable O-Mo domain is hereby interpreted as regular stacking; the smaller Mg-Mo region may be considered as 2D defect zone.…”

Model systems in heterogeneous catalysis: towards the design and understanding of structure and electronic properties

“…This is due to the large mismatch which usually exists between the metal and the oxide lattice (e.g. NiO(100)/Ni(100) 24 ). There are a few examples where well-ordered crystalline lms can be obtained in this way (e.g.…”