Observation of a New Ordered Structure of Oxygen on W(110)

2000 ◽  
Vol 619 ◽  
Author(s):  
D. E. Muzzall ◽  
S. Chiang
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Low Energy ◽  
Scanning Tunneling ◽  
Ordered Structure ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
The Matrix ◽  
Low Energy Electron ◽  
Stm Images

ABSTRACTUsing both low energy electron diffraction (LEED) and scanning tunneling microscopy (STM), we have made the first observation of a new ordered surface structure of oxygen on W(110). This structure is characterized by the matrix relative to the (1×1) W(110) structure, in which 15 tungsten atoms make up the rectangular unit cell. Based on high resolution STM images, a model for the structure is proposed which includes 6 adsorbed oxygen atoms and has a coverage of 0.40 ML.

COMBINED HRLEED AND STM INVESTIGATIONS ON THE INITIAL STAGES OF Cu HETEROEPITAXY Ru(0001)

1997 ◽  
Vol 04 (06) ◽  
pp. 1167-1171 ◽  
Author(s):  
CH. AMMER ◽  
K. MEINEL ◽  
H. WOLTER ◽  
A. BECKMANN ◽  
H. NEDDERMEYER
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Strain Relaxation ◽  
Local Scale ◽  
Low Energy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
Layer Structures ◽  
Low Energy Electron

Recent scanning tunneling microscopy (STM) observations revealed different layer structures in the heteroepitaxial Cu/Ru(0001) system with increasing film thickness attributed to various stages of strain relaxation. High-resolution low-energy electron diffraction (HRLEED) analysis permits one to derive more exactly both lattice periodicities and lattice rotations. Furthermore, the representative character of local STM results can be proved. However, STM measurements are needed to identify and to assign the satellite spots to coexistent different superstructures which are superposed incoherently in the diffraction pattern. Generally, the integral LEED results confirm the crystallographic data obtained by STM in a local scale.

An STM Observation of the Initial Process of Graphitization at the ${\rm 6H \mbox-SiC}(000{\bar 1})$ Surface

2003 ◽  
Vol 10 (02n03) ◽  
pp. 473-477 ◽  
Author(s):  
M. Naitoh ◽  
M. Kitada ◽  
S. Nishigaki ◽  
N. Toyama ◽  
F. Shoji
Keyword(s):  
Electron Diffraction ◽  
Low Energy ◽  
Scanning Tunneling ◽  
Graphite Layer ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Stm Image ◽  
Stm Images ◽  
Initial Process

We applied scanning tunneling microscopy (STM) as well as low-energy electron diffraction (LEED) to analyze the initial process of graphitization at [Formula: see text] surfaces. After annealing a [Formula: see text] surface at 1200°C, there appeared many domains with a single graphite layer in the STM image. Each graphite domain was azimuthally disordered to each other. Many large and small domains with various periodicities were observed in the STM image taken after annealing the surface at temperatures higher than 1300°C. These STM images can be explained as Moiré patterns due to different combinations of two graphite layers. In a LEED pattern azimuthally rotated graphite 1 × 1 spots are observed together with the fundamental 6H-SiC(0001)(1 × 1) spots, in consistent with the STM result.

scholarly journals Lateral ordering of PTCDA on the clean and the oxygen pre-covered Cu(100) surface investigated by scanning tunneling microscopy and low energy electron diffraction

2014 ◽  
Vol 10 ◽  
pp. 2055-2064 ◽  
Author(s):  
Stefan Gärtner ◽  
Benjamin Fiedler ◽  
Oliver Bauer ◽  
Antonela Marele ◽  
Moritz M Sokolowski
Keyword(s):  
Electron Diffraction ◽  
Scanning Tunneling Microscopy ◽  
Low Energy ◽  
Energy Electron ◽  
Scanning Tunneling ◽  
Structure Model ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Lattice Planes

We have investigated the adsorption of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) on the clean and on the oxygen pre-covered Cu(100) surface [referred to as (√2 × 2√2)R45° – 2O/Cu(100)] by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). Our results confirm the (4√2 × 5√2)R45° superstructure of PTCDA/Cu(100) reported by A. Schmidt et al. [J. Phys. Chem. 1995, 99,11770–11779]. However, contrary to Schmidt et al., we have no indication for a dissociation of the PTCDA upon adsorption, and we propose a detailed structure model with two intact PTCDA molecules within the unit cell. Domains of high lateral order are obtained, if the deposition is performed at 400 K. For deposition at room temperature, a significant density of nucleation defects is found pointing to a strong interaction of PTCDA with Cu(100). Quite differently, after preadsorption of oxygen and formation of the (√2 × 2√2)R45° – 2O/Cu(100) superstructure on Cu(100), PTCDA forms an incommensurate monolayer with a structure that corresponds well to that of PTCDA bulk lattice planes.

Sign in / Sign up

Export Citation Format

Share Document