کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5426583 | 1395892 | 2006 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Novel mesoscale defect structure on NiO(1 0 0) surfaces by atomic force microscopy Novel mesoscale defect structure on NiO(1 0 0) surfaces by atomic force microscopy](/preview/png/5426583.png)
Cleaved NiO(1 0 0) surfaces were imaged with atomic force microscopy (AFM) to determine defect concentrations and morphology. Random ã0 1 0ã and ã0 0 1ã oriented steps, which have been previously characterized, were the most common defect observed on the cleaved surface and formed with step heights in multiples of 2.1 à , the Ni-O nearest-neighbor distance, and terrace widths in the range of 25-100 nm. In addition, the surface showed novel mesoscale (â¼0.5-2 μm) square pyramidal defects with the pyramid base oriented along ã1 0 0ã symmetry related directions. Upon etching, the pyramidal defects converted to more stable cubic pits, consistent with (1 0 0) symmetry related walls. The square pyramidal pits tended to cluster or to form along step edges, where the weakened structure is more susceptible to surface deformations. Also, a small concentration of square pyramidal pits, oriented with the base of the pyramid along ã0 1 1ã, was observed on the cleaved NiO surfaces. For comparison purposes, chemical mechanical polished (CMP) NiO(1 0 0) substrates were imaged with AFM. Defect concentrations were of comparable levels to the cleaved surface, but showed a different distribution of defect types. Long-ranged stepped defects were much less common on CMP substrates, and the predominant defects observed were cubic pits with sidewalls steeper than could be accurately measured by the AFM tip. These defects were similar in size and structure to those observed on cleaved NiO(1 0 0) surfaces that had been acid etched, although pit clustering was more pronounced for the CMP surfaces.
Journal: Surface Science - Volume 600, Issue 17, 1 September 2006, Pages 229-235