scholarly journals Bulk magnetic domain structures visualized by neutron dark-field imaging

2008 ◽  
Vol 93 (11) ◽  
pp. 112504 ◽  
Author(s):  
C. Grünzweig ◽  
C. David ◽  
O. Bunk ◽  
M. Dierolf ◽  
G. Frei ◽  
...  
Keyword(s):  
Magnetic Domain ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Domain Structures ◽  
Field Imaging

scholarly journals Frequency-Induced Bulk Magnetic Domain-Wall Freezing Visualized by Neutron Dark-Field Imaging

2016 ◽  
Vol 6 (2) ◽  
Author(s):  
B. Betz ◽  
P. Rauscher ◽  
R. P. Harti ◽  
R. Schäfer ◽  
H. Van Swygenhoven ◽  
...  
Keyword(s):  
Domain Wall ◽  
Magnetic Domain ◽  
Dark Field ◽  
Magnetic Domain Wall ◽  
Dark Field Imaging ◽  
Field Imaging

Detection of a point defect in a silicon single crystal by high-resolution TEM

1995 ◽  
Vol 53 ◽  
pp. 466-467
Author(s):  
M. Awaji
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Point Defect ◽  
Point Defects ◽  
Noise Level ◽  
Dark Field ◽  
Silicon Single Crystal ◽  
High Resolution Image ◽  
Dark Field Imaging ◽  
Field Imaging

It is necessary to improve the resolution, brightness and signal-to-noise ratio(s/n) for the detection and identification of point defects in crystals. In order to observe point defects, multi-beam dark-field imaging is one of the useful methods. Though this method can improve resolution and brightness compared with dark-field imaging by diffuse scattering, the problem of s/n still exists. In order to improve the exposure time due to the low intensity of the dark-field image and the low resolution, we discuss in this paper the bright-field high-resolution image and the corresponding subtracted image with reference to a changing noise level, and examine the possibility for in-situ observation, identification and detection of the movement of a point defect produced in the early stage of damage process by high energy electron bombardment.The high-resolution image contrast of a silicon single crystal in the [10] orientation containing a triple divacancy cluster is calculated using the Cowley-Moodie dynamical theory and for a changing gaussian noise level. This divacancy model was deduced from experimental results obtained by electron spin resonance. The calculation condition was for the lMeV Berkeley ARM operated at 800KeV.

scholarly journals Noninvasive, in vivo assessment of the cervical microcirculation using incident dark field imaging

2021 ◽  
Vol 135 ◽  
pp. 104145
Author(s):  
Yani P. Latul ◽  
Arnoud W. Kastelein ◽  
Patricia W.T. Beemster ◽  
Nienke E. van Trommel ◽  
Can Ince ◽  
...  
Keyword(s):  
Dark Field ◽  
Dark Field Imaging ◽  
Incident Dark Field Imaging ◽  
Field Imaging ◽  
In Vivo Assessment

scholarly journals Correlation of image quality parameters with tube voltage in X-ray dark-field chest radiography: a phantom study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreas P. Sauter ◽  
Jana Andrejewski ◽  
Manuela Frank ◽  
Konstantin Willer ◽  
Julia Herzen ◽  
...  
Keyword(s):  
Image Quality ◽  
Imaging Modality ◽  
Signal Strength ◽  
Dark Field ◽  
Tube Voltage ◽  
X Ray ◽  
Dose Area Product ◽  
Dark Field Imaging ◽  
Field Imaging

AbstractGrating-based X-ray dark-field imaging is a novel imaging modality with enormous technical progress during the last years. It enables the detection of microstructure impairment as in the healthy lung a strong dark-field signal is present due to the high number of air-tissue interfaces. Using the experience from setups for animal imaging, first studies with a human cadaver could be performed recently. Subsequently, the first dark-field scanner for in-vivo chest imaging of humans was developed. In the current study, the optimal tube voltage for dark-field radiography of the thorax in this setup was examined using an anthropomorphic chest phantom. Tube voltages of 50–125 kVp were used while maintaining a constant dose-area-product. The resulting dark-field and attenuation radiographs were evaluated in a reader study as well as objectively in terms of contrast-to-noise ratio and signal strength. We found that the optimum tube voltage for dark-field imaging is 70 kVp as here the most favorable combination of image quality, signal strength, and sharpness is present. At this voltage, a high image quality was perceived in the reader study also for attenuation radiographs, which should be sufficient for routine imaging. The results of this study are fundamental for upcoming patient studies with living humans.

Transmission Electron Microscope Investigation of Sputtered Co-Pt Thin Films

1985 ◽  
Vol 48 ◽  
Author(s):  
P. Alexopoulos ◽  
R. H. Geiss ◽  
M. Schlenker
Keyword(s):  
Thin Films ◽  
Elevated Temperatures ◽  
Hexagonal Phase ◽  
Substantial Reduction ◽  
Magnetic Domain ◽  
Dark Field ◽  
Carbon Substrate ◽  
Dark Field Imaging ◽  
Carbon Substrates ◽  
Carbon Coated

ABSTRACTThin films of Co-10 at% Pt, ranging from 15 to 90 nm in thickness, have been DC-sputtered at various temperatures on to carbon-coated mica, carbon substrates on copper grids, or (001) silicon single crystals under 3 μm pressure of Ar, using targets of the alloy in the hexagonal phase, at growth rates of 9 nm/min. The samples were investigated by TEM, using bright-and dark-field imaging, lattice imaging, selected area diffraction and both Fresnel and focussed Lorentz modes. The primary structure of the films was found to be hexagonal, with a = 0.255 nm and c = 0.414 nm. For the samples sputtered at room temperature, the grain sizes were on the order of 0.μm on carbon-coated mica and carbon-substrate grids, and approximately an order of magnitude smaller on silicon substrates. Heavy streaking along the [001] of the hexagonal matrix was observed on diffraction patterns for grains having the [001] parallel to the surface; this streaking was found to be associated with the presence of a high density of faults parallel to the (001). In films sputtered on to carbon-coated mica at 225 °C, where a substantial reduction of the coercivity is observed, the overwhelming majority of the grains had the (001) basal plane parallel to the surface. Lorentz microscopy showed the magnetic domain structure in films grown on silicon to be markedly different from those grown on the carbon substrates, and further changes occurred for the films grown at elevated temperatures.

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