Analysis of 11 Myr of geomagnetic intensity variation

1998 ◽  
Vol 103 (B8) ◽  
pp. 17735-17748 ◽  
Author(s):  
Catherine G. Constable ◽  
Lisa Tauxe ◽  
Robert L. Parker
Keyword(s):  
Intensity Variation ◽  
Geomagnetic Intensity

First archaeomagnetic results from Colombia (the Bogotá Savanna Pre-Hispanic sites): Implications for the Caribbean absolute geomagnetic intensity variation curve

2019 ◽  
Vol 26 ◽  
pp. 101898
Author(s):  
Rubén Cejudo ◽  
Avto Goguitchaichvili ◽  
Fernando Montejo ◽  
Rafael García Ruiz ◽  
Álvaro Botiva ◽  
...  
Keyword(s):  
Intensity Variation ◽  
Variation Curve ◽  
The Caribbean ◽  
Geomagnetic Intensity

Geomagnetic intensity variation during the last 4000 years

1989 ◽  
Vol 56 (1-2) ◽  
pp. 49-58 ◽  
Author(s):  
Martin J. Aitken ◽  
Adrian L. Allsop ◽  
Gillian D. Bussell ◽  
Mona B. Winter
Keyword(s):  
Intensity Variation ◽  
Geomagnetic Intensity

Effect of strain on ADF-STEM high-resolution images

1991 ◽  
Vol 49 ◽  
pp. 666-667
Author(s):  
M. Kelly ◽  
D.M. Bird
Keyword(s):  
High Resolution ◽  
Strong Influence ◽  
Intensity Variation ◽  
Dark Field ◽  
Atomic Resolution ◽  
Strain Fields ◽  
High Resolution Image ◽  
Annular Dark Field ◽  
High Resolution Images ◽  
Interesting Alternative

It is well known that strain fields can have a strong influence on the details of HREM images. This, for example, can cause problems in the analysis of edge-on interfaces between lattice mismatched materials. An interesting alternative to conventional HREM imaging has recently been advanced by Pennycook and co-workers where the intensity variation in the annular dark field (ADF) detector is monitored as a STEM probe is scanned across the specimen. It is believed that the observed atomic-resolution contrast is correlated with the intensity of the STEM probe at the atomic sites and the way in which this varies as the probe moves from cell to cell. As well as providing a directly interpretable high-resolution image, there are reasons for believing that ADF-STEM images may be less suseptible to strain than conventional HREM. This is because HREM images arise from the interference of several diffracted beams, each of which is governed by all the excited Bloch waves in the crystal.

Contrast in Scanning Images of Thin Crystals

1972 ◽  
Vol 30 ◽  
pp. 520-521
Author(s):  
S. Kimoto ◽  
H. Hashimoto ◽  
S. Takashima ◽  
R. M. Stern ◽  
T. Ichinokawa
Keyword(s):  
Crystal Surface ◽  
Solid Angle ◽  
Incident Angle ◽  
Intensity Variation ◽  
Lattice Defects ◽  
Scanning Microscope ◽  
Electron Detector ◽  
Backscattered Electrons ◽  
Electron Image ◽  
Backscattered Electron

The most well known application of the scanning microscope to the crystals is known as Coates pattern. The contrast of this image depends on the variation of the incident angle of the beam to the crystal surface. The defect in the crystal surface causes to make contrast in normal scanning image with constant incident angle. The intensity variation of the backscattered electrons in the scanning microscopy was calculated for the defect in the crystals by Clarke and Howie. Clarke also observed the defect using a scanning microscope.This paper reports the observation of lattice defects appears in thin crystals through backscattered, secondary and transmitted electron image. As a backscattered electron detector, a p-n junction detector of 0.9 π solid angle has been prepared for JSM-50A. The gain of the detector itself is 1.2 x 104 at 50 kV and the gain of additional AC amplifier using band width 100 Hz ∼ 10 kHz is 106.

Convergent-beam thickness determination: The advantages of digital imaging

1994 ◽  
Vol 52 ◽  
pp. 420-421
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Intensity Variation ◽  
Convergent Beam Electron Diffraction ◽  
Digital Data ◽  
Thickness Determination ◽  
Frequent Use ◽  
Automated Processing ◽  
Beam Thickness ◽  
Convergent Beam ◽  
Remarkable Agreement

Convergent-beam electron diffraction (CBED) patterns contain an immense amount of information relating to the structure of the material from which they are obtained. The analysis of these patterns has progressed to the point that under appropriate, well specified conditions, the intensity variation within the CBED discs may be understood in a quantitative sense. Rossouw et al for example, have produced numerical simulations of zone-axis CBED patterns which show remarkable agreement with experimental patterns. Spence and co-workers have obtained the structure factor parameters for lowindex reflections using the intensity variation in 2-beam CBED patterns. Both of these examples involve the use of digital data. Perhaps the most frequent use for quantitative CBED analysis is the thickness determination described by Kelly et al. This analysis has been implemented in a variety of different ways; from real-time, in-situ analysis using the microscope controls, to measurements of photographic prints with a ruler, to automated processing of digitally acquired images. The potential advantages of this latter process will be presented.

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