Imaging The Atomic-Scale Structure of Molybdenum and Vanadium Oxides by Scanning Tunneling Microscopy

1994 ◽  
Vol 332 ◽  
Author(s):  
Gregory S. Rohrer ◽  
Weier Lu ◽  
Richard L. Smith
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Chemical Vapor ◽  
Shear Plane ◽  
Structural Features ◽  
Atomic Scale ◽  
Constant Current ◽  
Chemical Vapor Transport ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Coordination Polyhedra

ABSTRACTSingle crystals of Na0.003V2O5 and Mo18O52 were grown by chemical vapor transport and cleaved surfaces were imaged in ultrahigh vacuum using scanning tunneling microscopy (STM). Because the Mo18O52 (100) and Na0.003V2O5 (010) surfaces of these layered materials have a bulk terminated structure, the atomic-scale contrast in constant current images can be directly compared to components of the bulk structure. Among the structural features identified in the STM images are the surface/crystallographic shear plane intersections, the different MoOx coordination polyhedra on the Mo18O52 (100) surface, and the VO5 square pyramids that make up the Na0.003V2O5 (010) surface. In each of these cases, it was found that the atoms closest to the tip dominate the image contrast.

Scanning tunneling microscopy of polymers: A status report

1989 ◽  
Vol 47 ◽  
pp. 330-331
Author(s):  
P.E. Russell ◽  
I.H. Musselman
Keyword(s):  
High Resolution ◽  
Scanning Tunneling Microscopy ◽  
Sample Surface ◽  
Atomic Scale ◽  
Constant Current ◽  
Scanning Tunneling ◽  
Status Report ◽  
Tunneling Microscopy ◽  
Research Issues ◽  
Wide Range

Scanning tunneling microscopy (STM) has evolved rapidly in the past few years. Major developments have occurred in instrumentation, theory, and in a wide range of applications. In this paper, an overview of the application of STM and related techniques to polymers will be given, followed by a discussion of current research issues and prospects for future developments. The application of STM to polymers can be conveniently divided into the following subject areas: atomic scale imaging of uncoated polymer structures; topographic imaging and metrology of man-made polymer structures; and modification of polymer structures. Since many polymers are poor electrical conductors and hence unsuitable for use as a tunneling electrode, the related atomic force microscopy (AFM) technique which is capable of imaging both conductors and insulators has also been applied to polymers.The STM is well known for its high resolution capabilities in the x, y and z axes (Å in x andy and sub-Å in z). In addition to high resolution capabilities, the STM technique provides true three dimensional information in the constant current mode. In this mode, the STM tip is held at a fixed tunneling current (and a fixed bias voltage) and hence a fixed height above the sample surface while scanning across the sample surface.

Cross-Sectional Scanning Tunneling Microscopy of III-V Semiconductor Structures

1994 ◽  
Vol 332 ◽  
Author(s):  
R. M. Feenstra ◽  
A. Vaterlaus ◽  
J. M. Woodall ◽  
D. A. Collins ◽  
T. C. McGill
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscopy ◽  
Electronic Spectroscopy ◽  
Structural Features ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Layered Semiconductor ◽  
Cross Sectional ◽  
Semiconductor Structures

ABSTRACTThe method of cross-sectional scanning tunneling microscopy (STM) is described. Illustrative examples are given of studies of III-V semiconductor systems, including low-temperature-grown (LT) GaAs, and InAs/GaSb superlattices. In each case, the STM permits the observation of structural features on an atomic scale. The associated electronic spectroscopy for states a few eV on either side of the Fermi-level can be determined. Such information is relevant for the operation of devices constructed from these layered semiconductor systems.

The Atomic-Scale Characterization of Defects on Cleaved Vanadium and Molybdenum Oxide Surfaces Using Stm

1994 ◽  
Vol 357 ◽  
Author(s):  
Gregory S. Rohrer ◽  
Richard L. Smith
Keyword(s):  
Atomic Scale ◽  
Constant Current ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Coordination Polyhedra ◽  
Single Crystal Surfaces ◽  
Surface Plane ◽  
Crystallographic Shear ◽  
Scale Characterization ◽  
Reliable Interpretation

AbstractScanning tunneling microscopy (STM) was used to determine the structure of cleaved, single crystal surfaces of V205, V6013, Mo18052, and Mo8023. 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 known bulk structures, it is possible to establish a reliable interpretation for the contrast in the STM images. A comparison of images from the V6013(001) and the V205(001) surfaces clearly shows that the surface V coordination polyhedra that are capped by vanadyl 0 can be distinguished from those that are not. This allows vacancies in the vanadyl 0 position to be identified on cleaved V205(001) surfaces. Mo18052(100) and Mo8023(010) provide models for two different characteristic types of surface/crystallographic shear (CS) plane intersections. The shear in Mo8023 lies in the (010) surface plane and creates dark contrast along the [001]. The CS planes in Mo18052, 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.

Scanning Tunneling Microscopy of Amorphous Carbon Films

1990 ◽  
Vol 48 (1) ◽  
pp. 318-319
Author(s):  
Mircea Fotino ◽  
D.C. Parks
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Amorphous Carbon ◽  
Carbon Films ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Amorphous Carbon Films ◽  
Image Optimization ◽  
Step Procedure ◽  
Stm Images

In the last few years scanning tunneling microscopy (STM) has made it possible and easily accessible to visualize surfaces of conducting specimens at the atomic scale. Such performance allows the detailed characterization of surface morphology in an increasing spectrum of applications in a wide variety of fields. Because the basic imaging process in STM differs fundamentally from its equivalent in other well-established microscopies, good understanding of the imaging mechanism in STM enables one to grasp the correct information content in STM images. It thus appears appropriate to explore by STM the structure of amorphous carbon films because they are used in many applications, in particular in the investigation of delicate biological specimens that may be altered through the preparation procedures.All STM images in the present study were obtained with the commercial instrument Nanoscope II (Digital Instruments, Inc., Santa Barbara, California). Since the importance of the scanning tip for image optimization and artifact reduction cannot be sufficiently emphasized, as stressed by early analyses of STM image formation, great attention has been directed toward adopting the most satisfactory tip geometry. The tips used here consisted either of mechanically sheared Pt/Ir wire (90:10, 0.010" diameter) or of etched W wire (0.030" diameter). The latter were eventually preferred after a two-step procedure for etching in NaOH was found to produce routinely tips with one or more short whiskers that are essentially rigid, uniform and sharp (Fig. 1) . Under these circumstances, atomic-resolution images of cleaved highly-ordered pyro-lytic graphite (HOPG) were reproducibly and readily attained as a standard criterion for easily recognizable and satisfactory performance (Fig. 2).

scholarly journals Incorporation of Bi atoms in InP studied at the atomic scale by cross-sectional scanning tunneling microscopy

2017 ◽  
Vol 1 (3) ◽  
Author(s):  
C. M. Krammel ◽  
M. Roy ◽  
F. J. Tilley ◽  
P. A. Maksym ◽  
L. Y. Zhang ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Cross Sectional

Room temperature observation of the correlation between atomic and electronic structure of graphene on Cu(110)

RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 98001-98009 ◽  
Author(s):  
Thais Chagas ◽  
Thiago H. R. Cunha ◽  
Matheus J. S. Matos ◽  
Diogo D. dos Reis ◽  
Karolline A. S. Araujo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Chemical Vapor Deposition ◽  
Scanning Tunneling Microscopy ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Temperature Observation ◽  
Atomic And Electronic Structure

We have used atomically-resolved scanning tunneling microscopy and spectroscopy to study the interplay between the atomic and electronic structure of graphene formed on copper via chemical vapor deposition.

Atomic-scale surface science phenomena studied by scanning tunneling microscopy

2009 ◽  
Vol 603 (10-12) ◽  
pp. 1315-1327 ◽  
Author(s):  
F. Besenbacher ◽  
J.V. Lauritsen ◽  
T.R. Linderoth ◽  
E. Lægsgaard ◽  
R.T. Vang ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Surface Science ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Scale Surface

scholarly journals Resolving Complex Atomic-Scale Spin Structures by Spin-Polarized Scanning Tunneling Microscopy

2001 ◽  
Vol 86 (18) ◽  
pp. 4132-4135 ◽  
Author(s):  
D. Wortmann ◽  
S. Heinze ◽  
Ph. Kurz ◽  
G. Bihlmayer ◽  
S. Blügel
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Spin Structures ◽  
Spin Polarized
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