In-situAnnular Bright-Field Imaging of Structural Transformation of Spinel LiV$_{2}$O$_{4}$ Crystals into Defective Li$_{x}$V$_{2}$O$_{4}$

2012 ◽  
Vol 51 ◽  
pp. 020202 ◽  
Author(s):  
Soyeon Lee ◽  
Yoshifumi Oshima ◽  
Seiji Niitaka ◽  
Hidenori Takagi ◽  
Yasumasa Tanishiro ◽  
...  
2012 ◽  
Vol 51 (2R) ◽  
pp. 020202
Author(s):  
Soyeon Lee ◽  
Yoshifumi Oshima ◽  
Seiji Niitaka ◽  
Hidenori Takagi ◽  
Yasumasa Tanishiro ◽  
...  

Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.


Microscopy ◽  
2016 ◽  
Author(s):  
Yoshifumi Oshima ◽  
Soyeon Lee ◽  
Kunio Takayanagi

2009 ◽  
Vol 63 (11) ◽  
pp. 1197-1203 ◽  
Author(s):  
E. D. Emmons ◽  
A. Tripathi ◽  
J. A. Guicheteau ◽  
S. D. Christesen ◽  
A. W. Fountain

Raman chemical imaging (RCI) has been used to detect and identify explosives in contaminated fingerprints. Bright-field imaging is used to identify regions of interest within a fingerprint, which can then be examined to determine their chemical composition using RCI and fluorescence imaging. Results are presented where explosives in contaminated fingerprints are identified and their spatial distributions are obtained. Identification of explosives is obtained using Pearson's cosine cross-correlation technique using the characteristic region (500–1850 cm−1) of the spectrum. This study shows the ability to identify explosives nondestructively so that the fingerprint remains intact for further biometric analysis. Prospects for forensic examination of contaminated fingerprints are discussed.


2020 ◽  
Vol 216 ◽  
pp. 113023
Author(s):  
Willem Tichelaar ◽  
Wim J.H. Hagen ◽  
Tatiana E. Gorelik ◽  
Liang Xue ◽  
Julia Mahamid
Keyword(s):  

Author(s):  
M.M.G. Latting ◽  
W. Walkosz ◽  
R.F. Klie

Annular Bright Field (ABF) is a relatively new method of Scanning Transmission Electron Microscopy (STEM) imaging that is desirable because of its ability to provide additional visual information in terms of showing lightweight atoms, whereas standard dark field imaging does not. In order to better understand the parameters necessary to perfect this method, this research article aimed to study a specific property of this imaging method: the dependence of sample thickness on image quality and atomic resolution. Multislice calculations were utilized to generate atomic potentials that were used to simulate different thicknesses of β-Si3N4. The resulting images were then examined to measure atomic full width at half-maximum (FWHM) in order to have a quantifiable value to support visual selection of the best ABF output image. Comparison of image quality/atomic resolution and FWHM values suggested that as a general trend, as sample thickness increases, atomic resolution and image quality deteriorate, citing Huygens' Principle of Classical Optics via the propagation of spherical electron waves through a vacuum. This study will bring a new awareness to the necessary precision required by researchers' sample preparation during Annular Bright Field imaging to yield the best image of their respective samples.


Sign in / Sign up

Export Citation Format

Share Document