The atomic-scale characterization of defects on cleaved vanadium and molybdenum oxide surfaces using STM
- Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering
Scanning tunneling microscopy (STM) was used to determine the structure of cleaved, single crystal surfaces of V{sub 2}O{sub 5}, V{sub 6}O{sub 13}, Mo{sub 18}O{sub 52}, and Mo{sub 8}O{sub 23}. Constant current images were recorded in ultrahigh vacuum and in air. By imaging well-defined surfaces that exhibit structural and chemical similarities, and comparing the observations to the know bulk structures, it is possible to establish a reliable interpretation for the contrast in the STM images. A comparison of images from the V{sub 6}O{sub 13}(001) and the V{sub 2}O{sub 5}(001) surfaces clearly shows that the surface V coordination polyhedra that are capped by vanadyl O can be distinguished from those that are not. This allows vacancies in the vanadyl O position to be identified on cleaved V{sub 2}O{sub 5}(001) surfaces. Mo{sub 18}O{sub 52}(001) and Mo{sub 8}O{sub 23}(010) provide models for two different characteristic types of surface/crystallographic shear (CS) plane intersections. The shear in Mo{sub 8}O{sub 23} lies in the (010) surface plane and creates dark contrast along the [001]. The CS planes in Mo{sub 18}O{sub 52}, on the other hand, have components of shear both in and normal to the (100) surface plane and create white contrast parallel to [010]. These standards for contrast identification can be used to identify defects on inhomogeneous surfaces.
- OSTI ID:
- 94039
- Report Number(s):
- CONF-941144-; ISBN 1-55899-258-8; TRN: 95:018715
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 28 Nov - 9 Dec 1994; Other Information: PBD: 1995; Related Information: Is Part Of Structure and properties of interfaces in ceramics; Bonnell, D. [ed.] [Univ. of Pennsylvania, Philadelphia, PA (United States)]; Ruehle, M. [ed.] [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany)]; Chowdhry, U. [ed.] [E.I. duPont de Nemours and Co., Inc., Wilmington, DE (United States)]; PB: 481 p.; Materials Research Society symposium proceedings, Volume 357
- Country of Publication:
- United States
- Language:
- English
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