Characterizing In and N impurities in GaAs fromab initiocomputer simulation of (110) cross-sectional STM images

2007 ◽  
Vol 75 (3) ◽  
Author(s):  
Xiangmei Duan ◽  
Maria Peressi ◽  
Stefano Baroni
Keyword(s):  
Cross Sectional ◽  
Stm Images

Interpreting interfacial structure in cross-sectional STM images of III–V semiconductor heterostructures

2000 ◽  
Vol 465 (3) ◽  
pp. 361-371 ◽  
Author(s):  
B.Z. Nosho ◽  
W. Barvosa-Carter ◽  
M.J. Yang ◽  
B.R. Bennett ◽  
L.J. Whitman
Keyword(s):  
Semiconductor Heterostructures ◽  
Interfacial Structure ◽  
Cross Sectional ◽  
Stm Images

SURFACE NANOPATTERNING EFFECTS, STRUCTURE AND MAGNETIC PROPERTIES OF EPITAXIAL Ni FILMS

2004 ◽  
Vol 03 (06) ◽  
pp. 737-748
Author(s):  
R. A. LUKASZEW ◽  
Z. ZHANG ◽  
D. PEARSON ◽  
X. PAN ◽  
R. CLARKE ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Molecular Beam ◽  
Uniaxial Anisotropy ◽  
Neutron Reflectivity ◽  
Azimuthal Dependence ◽  
Cross Sectional ◽  
Azimuthal Symmetry ◽  
Interfacial Surface ◽  
Stm Images

We have studied the correlation between film structures and the azimuthal dependence of the magnetization reversal in (001) and (111) Ni films grown on MgO substrates using molecular beam epitaxy (MBE). For as-grown (001) Ni films, the coercive field exhibits four-fold azimuthal symmetry while in-situ annealed films exhibit additional uniaxial anisotropy. In-situ STM images show surface stripe nanopatterning on the annealed films, which is absent in the as-grown ones. Cross sectional TEM seems to indicate the presence of a highly ordered interfacial layer that we postulate may be fcc NiO . Tetragonal distortion of this layer upon annealing may have induced the uniaxial anisotropy observed in the magnetic properties. Polarized neutron reflectivity measurements performed on some of the films are correlated with the interfacial surface structure and the magnetic anisotropy.

Recent Development and Application of the XSTM

1998 ◽  
Vol 05 (03n04) ◽  
pp. 797-802 ◽  
Author(s):  
H. Hirayama ◽  
Y. Einaga ◽  
M. Koike ◽  
K. Takayanagi
Keyword(s):  
Cross Section ◽  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Local Surface ◽  
Cross Sectional ◽  
Sample Bias ◽  
Disordered Phase ◽  
The Cross ◽  
Sectional Surface ◽  
Stm Images

The development of the cross-section scanning tunneling microscope (XSTM) and its application to the study of the cross-section of boron(B)-implanted Si wafers are reported. To obtain a cross-section of wafer samples, we examined the cleavage on the {111} plane in two ways. As a result the cleavage, by pushing the side of the sample wafer, was found to be preferable in obtaining a flat {111} cross-section from both (111) and (001) wafers. Our devices in the mounting angle and the guiding line for the cleavage are also described in detail, Using this XSTM, we observed the {111} cleaved cross-sectional surface of the B-implanted Si(111) wafer, The local surface structure was found to change on the cleaved cross-section from the 7 × 7 to the [Formula: see text] reconstruction through the disordered phase, The change was found to be consistent with the depth profile of the implanted B in the Si water. The arrangement of B and Si atoms in the disordered phase was determined by the site and the sample bias dependence of protrusions in STM images.

Automated Image Analysis Of Nuclear And Cytoplasmic Changes In Exfoliated Cells From Tracheas Treated With Carcinogen

1977 ◽  
Vol 35 ◽  
pp. 220-221
Author(s):  
S.F. Stinson ◽  
J.C. Lilga ◽  
M.B. Sporn
Keyword(s):  
Image Analysis ◽  
Pattern Analysis ◽  
Relative Proportion ◽  
Automated Image Analysis ◽  
Image Analyzer ◽  
Cross Sectional ◽  
Exfoliated Cells ◽  
Neoplastic Lesions ◽  
Analysis System ◽  
Morphologic Criterion

Increased nuclear size, resulting in an increase in the relative proportion of nuclear to cytoplasmic sizes, is an important morphologic criterion for the evaluation of neoplastic and pre-neoplastic cells. This paper describes investigations into the suitability of automated image analysis for quantitating changes in nuclear and cytoplasmic cross-sectional areas in exfoliated cells from tracheas treated with carcinogen.Neoplastic and pre-neoplastic lesions were induced in the tracheas of Syrian hamsters with the carcinogen N-methyl-N-nitrosourea. Cytology samples were collected intra-tracheally with a specially designed catheter (1) and stained by a modified Papanicolaou technique. Three cytology specimens were selected from animals with normal tracheas, 3 from animals with dysplastic changes, and 3 from animals with epidermoid carcinoma. One hundred randomly selected cells on each slide were analyzed with a Bausch and Lomb Pattern Analysis System automated image analyzer.

X-Ray Replication of Submicrometer Linewidth Patterns

1977 ◽  
Vol 35 ◽  
pp. 136-137
Author(s):  
Henry I. Smith ◽  
D.C. Flanders
Keyword(s):  
Electron Beam Lithography ◽  
Cross Sectional ◽  
X Ray ◽  
Electron Backscattering ◽  
Spatial Frequencies ◽  
Cross Sectional Profile ◽  
Carbon Foils ◽  
Sectional Profile ◽  
And Control ◽  
Soft Radiation

Scanning electron beam lithography has been used for a number of years to write submicrometer linewidth patterns in radiation sensitive films (resist films) on substrates. On semi-infinite substrates, electron backscattering severely limits the exposure latitude and control of cross-sectional profile for patterns having fundamental spatial frequencies below about 4000 Å(l),Recently, STEM'S have been used to write patterns with linewidths below 100 Å. To avoid the detrimental effects of electron backscattering however, the substrates had to be carbon foils about 100 Å thick (2,3). X-ray lithography using the very soft radiation in the range 10 - 50 Å avoids the problem of backscattering and thus permits one to replicate on semi-infinite substrates patterns with linewidths of the order of 1000 Å and less, and in addition provides means for controlling cross-sectional profiles. X-radiation in the range 4-10 Å on the other hand is appropriate for replicating patterns in the linewidth range above about 3000 Å, and thus is most appropriate for microelectronic applications (4 - 6).

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Computer Reconstruction of the Cellular Architecture of the Daphnia Magna Optic Ganglion

1975 ◽  
Vol 33 ◽  
pp. 284-285
Author(s):  
E. R. Macagno ◽  
C. Levinthal
Keyword(s):  
Daphnia Magna ◽  
Genetic Background ◽  
Compound Eye ◽  
Synaptic Connectivity ◽  
Serial Sections ◽  
Cross Sectional ◽  
Small Crustacean ◽  
Optic Ganglion ◽  
Structural Invariance ◽  
High Degree

The optic ganglion of Daphnia Magna, a small crustacean that reproduces parthenogenetically contains about three hundred neurons: 110 neurons in the Lamina or anterior region and about 190 neurons in the Medulla or posterior region. The ganglion lies in the midplane of the organism and shows a high degree of left-right symmetry in its structures. The Lamina neurons form the first projection of the visual output from 176 retinula cells in the compound eye. In order to answer questions about structural invariance under constant genetic background, we have begun to reconstruct in detail the morphology and synaptic connectivity of various neurons in this ganglion from electron micrographs of serial sections (1). The ganglion is sectioned in a dorso-ventra1 direction so as to minimize the cross-sectional area photographed in each section. This area is about 60 μm x 120 μm, and hence most of the ganglion fit in a single 70 mm micrograph at the lowest magnification (685x) available on our Zeiss EM9-S.

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