Al Induced Reconstructions on the Si(111) Surfaces Studied by Scanning Tunneling Microscopy

1992 ◽  
Vol 295 ◽  
Author(s):  
Masamichi Yoshimura ◽  
Katsuya Takaoka ◽  
Takafumi Yao ◽  
Tomoshige Sato ◽  
Takashi Sueyoshi ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Scanning Tunneling Microscopy ◽  
Unit Cell ◽  
Incommensurate Phase ◽  
Scanning Tunneling ◽  
Misfit Dislocations ◽  
Dangling Bond ◽  
Tunneling Microscopy ◽  
Stm Images ◽  
Incommensurate Phases

AbstractThe atomic arrangements of the α-7×7 phase and incommensurate phases of Al adsorbed Si(111) surface are investigated respectively by scanning tunneling microscopy (STM). STM images of α-7×7 surface reveal that characteristic triangular structures consisting of three Al adatoms situated on the center part of each half unit cell. The three Al adatoms form a triangular cluster and are bonded to the center adatoms. In this situation, the dangling bond of the center adatom is saturated, which would modify its electronic structure into non-metallic. The incommensurate phase is consists of approximately 9×9 structures, which are separated each other with misfit dislocations. In the “9×9” structure, individual Al atom is visible arranged in threefold symmetry.

AN STM STUDY OF THE (2×4) AND c(4×4) RECONSTRUCTIONS FORMED ON GaAs(001) BY MOLECULAR BEAM EPITAXY

1994 ◽  
Vol 01 (04) ◽  
pp. 621-624 ◽  
Author(s):  
A.R. AVERY ◽  
D.M. HOLMES ◽  
T.S. JONES ◽  
B.A. JOYCE
Keyword(s):  
Molecular Beam Epitaxy ◽  
Scanning Tunneling Microscopy ◽  
Molecular Beam ◽  
Unit Cell ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Unit Cells ◽  
Stm Images

Atomic resolution scanning tunneling microscopy (STM) has been used to study the Asterminated (2×4) and c(4×4) reconstructions formed on GaAs(001) surfaces grown in situ by molecular beam epitaxy (MBE). Filled states STM images of the (2×4) surface always showed unit cells consisting of two As dimers in the top layer. Cooling this surface under an As flux led initially to a highly kinked (2×4) phase before the transition to the c(4×4) structure. At no point were three As dimers observed in the top layer for the (2×4) unit cell. The c(4×4) structure involves the chemisorption of a second layer of As onto an already As-terminated surface. STM images of this surface showed a series of bright rectangular blocks consisting, when complete, of three pairs of As atoms.

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).

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.

scholarly journals The Effect of Deposition Time on the Surface Coverage of Sublimation Deposited Solid-Phase Glycine and Proline Molecules Measured by Scanning Tunneling Microscopy

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 2962
Author(s):  
Young-Sang Youn
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Room Temperature ◽  
Deposition Time ◽  
Surface Coverage ◽  
Solid Phase ◽  
Scanning Tunneling ◽  
Adsorption Model ◽  
Tunneling Microscopy ◽  
Langmuir Adsorption ◽  
Stm Images

The effect of deposition time on the surface coverage of sublimation deposited solid-phase glycine and proline molecules onto a Ge(100) surface was studied at room temperature using scanning tunneling microscopy (STM). The STM images obtained at various coverages of glycine and proline adsorbed on the Ge(100) surface showed that (i) the adsorption rate for both molecules gradually decreased with increasing deposition time, obeying the Langmuir adsorption model, and (ii) the coverage of glycine on the Ge(100) surface is higher than that of proline under the same deposition conditions, which may be due to the differences in their molecular weight or molecular sticking probability.

Local Electronic Structure in Ordered Aggregates of Carbon Nanotubes: Scanning Tunneling Microscopy/scanning Tunneling Spectroscopy Study

1998 ◽  
Vol 13 (9) ◽  
pp. 2389-2395 ◽  
Author(s):  
D. L. Carroll ◽  
P. M. Ajayan ◽  
S. Curran
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Structure ◽  
Scanning Tunneling Microscopy ◽  
Local Density ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Spatially Resolved ◽  
Local Electronic Structure

The recent application of tunneling probes in electronic structure studies of carbon nanotubes has proven both powerful and challenging. Using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS), local electronic properties in ordered aggregates of carbon nanotubes (multiwalled nanotubes and ropes of single walled nanotubes) have been probed. In this report, we present evidence for interlayer (concentric tube) interactions in multiwalled tubes and tube-tube interactions in singlewalled nanotube ropes. The spatially resolved, local electronic structure, as determined by the local density of electronic states, is shown to clearly reflect tube-tube interactions in both of these aggregate forms.

Scanning Tunneling Microscopy Imaging of Defects in Layered Compounds

1990 ◽  
Vol 209 ◽  
Author(s):  
G. P. E. M. Van Bakell ◽  
J. Th. M. De Hosson ◽  
T. Hibma
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Structural Features ◽  
Layered Compounds ◽  
Scanning Tunneling ◽  
X Ray Diffraction ◽  
Tunneling Microscopy ◽  
Microscopy Imaging ◽  
X Ray ◽  
Sample Orientation ◽  
Stm Images

ABSTRACTStructural features of TiS2 were studied by scanning tunneling microscopy (STM) and single-crystal X-ray diffraction was applied as a complementary technique. STM images in air and at room temperature revealed, beside the trigonal symmetry of the lattice, several new features having this symmetry as well. We conclude that these features not only are to be described by structural defect phenomena which affect octahedral sites in the 1T-CdI2 structure but tetrahedral sites as well. Sample orientation determination by X-ray diffraction provides a unique relation between feature types and sites. A model is proposed in which displaced Ti atoms account for the observed features.

scholarly journals Thermal evolution of the morphology of Ni/Ge(111)-c(2 × 8) surface

2014 ◽  
Vol 32 (4) ◽  
pp. 641-647 ◽  
Author(s):  
Agnieszka Tomaszewska ◽  
Jhen-Hao Li ◽  
Xiao-Lan Huang ◽  
Tsu-Yi Fu
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Room Temperature ◽  
Thermal Evolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Nucleation Sites ◽  
Dual Polarity ◽  
Stm Images

AbstractThe thermal evolution of the interface formed by room temperature (RT) deposition of Ni atoms (coverage 0.1, 0.5, 1.2 ML) onto a Ge(111)-c(2 × 8) surface has been studied with the use of scanning tunneling microscopy (STM). Atomically resolved STM images revealed that, at RT, the boundaries between the different c(2 × 8) domains acted as nucleation sites for Ni atoms. After annealing the surface with deposited material at 473 to 673 K the formation of nano-sized islands of NixGey compounds was observed. In addition, the occurrence of ring-like structures was recorded. Based on the dual-polarity images the latter were assigned to Ni atoms adsorbed on Ge adatoms.

Morphology and electronic structure of Gd wires studied with scanning tunneling microscopy

1998 ◽  
Vol 66 (7) ◽  
pp. S1195-S1198 ◽  
Author(s):  
A. Mühlig ◽  
T. Günther ◽  
A. Bauer ◽  
K. Starke ◽  
B.L. Petersen ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Scanning Tunneling Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy

Scanning tunneling microscopy/spectroscopy of dangling-bond wires fabricated on the Si(100)-2×1-H surface

1998 ◽  
Vol 130-132 ◽  
pp. 340-345 ◽  
Author(s):  
Taro Hitosugi ◽  
T Hashizume ◽  
S Heike ◽  
H Kajiyama ◽  
Y Wada ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Scanning Tunneling ◽  
Dangling Bond ◽  
Tunneling Microscopy ◽  
Bond Wires
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