Nanoscopic Molecular Engineering: Organic MBE and STM

1992 ◽  
Vol 247 ◽  
Author(s):  
Masahiko Hara ◽  
Anthony F. Garito ◽  
Hiroyuki Sasabe
Keyword(s):  
Molecular Beam ◽  
Molecular Engineering ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
New Approach ◽  
Molecular Systems ◽  
Novel Material ◽  
Low Dimensionality ◽  
Low Dimensional ◽  
Low Dimensional Materials

ABSTRACTApplication of molecular beam epitaxy (MBE) and scanning tunneling microscopy (STM), especially for organic molecular systems, has been drawing our attention as a new approach to realizing novel material structures with low dimensionality, which are expected to exhibit important electronic and photonic properties. The following is an outline of our work in progress, including an overview of “nanoscopic” molecular engineering. Future possibilities of fabrication, modification and characterization for organic low-dimensional materials are reviewed with the new concept embraced by “nanoscopic” science and technology.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

scholarly journals Nanostructured and Modulated Low-Dimensional Systems

2013 ◽  
Vol 203-204 ◽  
pp. 42-47
Author(s):  
Albert Prodan ◽  
Herman J.P. van Midden ◽  
Erik Zupanič ◽  
Rok Žitko
Keyword(s):  
Charge Density ◽  
Structural Information ◽  
Density Wave ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Additional Information ◽  
Related Pair ◽  
Good Accord ◽  
Long Range Ordering ◽  
Low Dimensional

Charge density wave (CDW) ordering in NbSe3 and the structurally related quasi one-dimensional compounds is reconsidered. Since the modulated ground state is characterized by unstable nano-domains, the structural information obtained from diffraction experiments is to be supplemented by some additional information from a method, able to reveal details on a unit cell level. Low-temperature (LT) scanning tunneling microscopy (STM) can resolve both, the local atomic structure and the superimposed charge density modulation. It is shown that the established model for NbSe3 with two incommensurate (IC) modes, q1 = (0,0.241,0) and q2 = (0.5,0.260,0.5), locked in at T1=144K and T2=59K and separately confined to two of the three available types of bi-capped trigonal prismatic (BCTP) columns, must be modified. The alternative explanation is based on the existence of modulated layered nano-domains and is in good accord with the available LT STM results. These confirm i.a. the presence of both IC modes above the lower CDW transition temperature. Two BCTP columns, belonging to a symmetry-related pair, are as a rule alternatively modulated by the two modes. Such pairs of columns are ordered into unstable layered nano-domains, whose q1 and q2 sub-layers are easily interchanged. The mutually interchangeable sections of the two unstable IC modes keep a temperature dependent long-range ordering. Both modes can formally be replaced by a single highly inharmonic long-period commensurate CDW.

scholarly journals Scanning Tunneling Microscopy Studies of InGaN Growth by Molecular Beam Epitaxy

1999 ◽  
Vol 4 (S1) ◽  
pp. 858-863
Author(s):  
Huajie Chen ◽  
A. R. Smith ◽  
R. M. Feenstra ◽  
D. W. Greve ◽  
J. E. Northrup
Keyword(s):  
Molecular Beam Epitaxy ◽  
Scanning Tunneling Microscopy ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Growth Parameters ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Group V ◽  
Group Iii ◽  
Ingan Alloys

InGaN alloys with indium compositions ranging from 0–40% have been grown by molecular beam epitaxy. The dependence of the indium incorporation on growth temperature and group III/group V ratio has been studied. Scanning tunneling microscopy images, interpreted using first-principles theoretical computations, show that there is strong indium surface segregation on InGaN. Based on this surface segregation, a qualitative model is proposed to explain the observed indium incorporation dependence on the growth parameters.

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