High Spatial Resolution EBSD Study of Nanosized Epitaxial Particles

1997 ◽  
Vol 3 (S2) ◽  
pp. 559-560
Author(s):  
F. Cosandey
Keyword(s):  
High Resolution ◽  
Orientation Relationship ◽  
Field Emission ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Electron Backscatter Diffraction ◽  
Resolution Limit ◽  
Electron Microscopes ◽  
Relationship Of ◽  
Scanning Electron

Traditionally, the structure and orientation relationship of individual catalyst particles on various oxide substrates have been studied by transmission electron microscopy. However, the combination of high resolution scanning electron microscopes (HRSEM) equipped with Schottky field emission sources with CCD cameras for recording electron backscatter diffraction (EBSD) paterns, it is now possible to obtain both morpholgy and orientation of individual particles with high spatial resolution. In this paper, we present results on the application of combined EBSD with HRSEM to determine the epitaxial orientation relationship of 80 nm Au particles on TiO2 (110). An evaluation of the spatial resolution limit of EBSD using Monte Carlo simulation of backscattered electron trajectories is also presented.The TiO2 (110) single crystal surfaces used in this study were prepared in UHV using surface science tools followed by in-situ metallization. After deposition of 15 nm Au at 300K followed by annealing at 800K, the samples were transferred in air to the Field Emission Scanning Electron microscope (LEO 982 Gemini) for high resolution imaging.

Direct Defect Imaging in the High Resolution Sem

1990 ◽  
Vol 183 ◽  
Author(s):  
David C Joy
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
High Performance ◽  
Necessary Conditions ◽  
Electron Channeling ◽  
Electron Microscopes ◽  
Crystallographic Defects ◽  
Scanning Electron Microscopes ◽  
Defect Imaging ◽  
Scanning Electron

AbstractThe theory of imaging crystallographic defects in solid specimens through the use of electron channeling contrast is reviewed and the necessary conditions for observation are deduced. It is shown that current high performance field emission scanning electron microscopes can meet these requirements and produce dislocation images from suitable materials.

A New High Resolution Field Emission SEM with Variable Pressure Capabilities

2001 ◽  
Vol 7 (S2) ◽  
pp. 880-881 ◽  
Author(s):  
Peter Gnauck ◽  
Volker Drexel ◽  
J. Greiser
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Low Voltage ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Chamber Pressure ◽  
Variable Pressure ◽  
Natural State ◽  
Electron Microscopes ◽  
Scanning Electron

To examine non conductive samples in their natural state (i.e. without significant sample preparation) at high resolution in the SEM the technique of low voltage field emission scanning electron microscopy (LVFESEM) is used. Due to the limitation in accelerating voltage (U<1kV) this technique is limited in respect of chemical analysis. Furthermore it is not possible to examine humid and outgassing samples in high vacuum. in recent years the application of variable pressure scanning electron microscopes (VPSEM) became an important technique in materials science as well as in life science. Due to the capability of maintaining a high chamber pressure humid, outgassing and non-conductive samples, can be examined in their natural state without significant sample modification or preparation. Especially compound materials with different electron yields can be imaged without any charging effects (Fig. 2), [2]. This paper describes a high resolution field emission electron microscope, that combines low voltage and variable pressure capabilities.The high pressure capabilities of the instrument are realized by eliminating the high vacuum requirements of SEM in the microscope chamber. This is done by separating the vacuum environment in the chamber from the ultra high vacuum environment in the gun area.

Low Voltage X-Ray Microanalysis of Bulk Bio-Organic Samples

1998 ◽  
Vol 4 (S2) ◽  
pp. 190-191
Author(s):  
Patrick Echlin
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Spatial Resolution ◽  
High Voltage ◽  
Biological Material ◽  
High Spatial Resolution ◽  
Low Voltage ◽  
Similar Type ◽  
The Other ◽  
X Ray

Although high resolution (2nm), low voltage (lkV), SEM of bio-organic materials can now be performed more or less routinely using instruments fitted with a field emission source, virtually no low voltage x-ray microanalysis has been carried out on this type of specimen. Boyes and Nockolds showed that quantitative microanalytical information could be obtained from polished inorganic samples at a spatial resolution of l00nm at 5kV and Johnson et al obtained similar type of data at a spatial resolution of 150nm at 3kV. High spatial resolution (l0nm) microanalysis can be achieved in frozen dried or chemically compromised sections of biological material examined at high voltage in the TEM but frozen hydrated chemically unfixed sections are damaged. The other approach is to use the SEM with frozen hydrated, chemically uncompromised samples, usually at about 10-15kV, in order to obtain sufficient signal from the elements of interest which typically lie in the range Na (Z=l 1) to Ca (Z=20).

Ultra-high resolution cinematic digital 3-D imaging of the cell surface by field-emission scanning electron microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 12-13
Author(s):  
Klaus-Ruediger Peters ◽  
Martin D. Fox
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Three Dimensional ◽  
Stereo Imaging ◽  
Information Display ◽  
Dynamic Perspective ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Image Details ◽  
Scanning Electron

Field emission scanning electron microscopes (FSEM) establish high resolution on rugged bulk surfaces. However, often visualization and recognition of image details are hindered by low contrasts. Retrieval of such obscured image information is possible with three-dimensional (3-D) imaging.3-D information can be accessed in several ways. At low magnifications direct TV-rate imaging is possible allowing continuous relocation of the specimen and deduction of 3-D information from dynamic changes of perspectives and parallax. Additionally, two images from different stereo perspectives can be simultaniously produced and 3-D information can directly be displayed through optical or electronic devices (stereo imaging). The combination of dynamic perspective changes and stereo-presentation matches the 3-D information input of the human visual system and provides an optimal tool for visual 3-D pattern recognition.At higher magnifications (>~10,000-20,000x) real time stereo imaging is not possible. 3-D information display becomes limited to stationary perspective displays generated with long frame times.

Field Emission SEM Equipped With Noise Compensator

1973 ◽  
Vol 31 ◽  
pp. 302-303
Author(s):  
S. Saito ◽  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Low Contrast ◽  
Probe Current ◽  
High Resolution Images ◽  
Scanning Electron

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.

scholarly journals Deriving VIIRS High-Spatial Resolution Water Property Data over Coastal and Inland Waters Using Deep Convolutional Neural Network

2021 ◽  
Vol 13 (10) ◽  
pp. 1944
Author(s):  
Xiaoming Liu ◽  
Menghua Wang
Keyword(s):  
Neural Network ◽  
High Resolution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Ocean Color ◽  
Super Resolution ◽  
Inland Waters ◽  
Coastal Oceans ◽  
Chl A ◽  
Color Data

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite has been a reliable source of ocean color data products, including five moderate (M) bands and one imagery (I) band normalized water-leaving radiance spectra nLw(λ). The spatial resolutions of the M-band and I-band nLw(λ) are 750 m and 375 m, respectively. With the technique of convolutional neural network (CNN), the M-band nLw(λ) imagery can be super-resolved from 750 m to 375 m spatial resolution by leveraging the high spatial resolution features of I1-band nLw(λ) data. However, it is also important to enhance the spatial resolution of VIIRS-derived chlorophyll-a (Chl-a) concentration and the water diffuse attenuation coefficient at the wavelength of 490 nm (Kd(490)), as well as other biological and biogeochemical products. In this study, we describe our effort to derive high-resolution Kd(490) and Chl-a data based on super-resolved nLw(λ) images at the VIIRS five M-bands. To improve the network performance over extremely turbid coastal oceans and inland waters, the networks are retrained with a training dataset including ocean color data from the Bohai Sea, Baltic Sea, and La Plata River Estuary, covering water types from clear open oceans to moderately turbid and highly turbid waters. The evaluation results show that the super-resolved Kd(490) image is much sharper than the original one, and has more detailed fine spatial structures. A similar enhancement of finer structures is also found in the super-resolved Chl-a images. Chl-a filaments are much sharper and thinner in the super-resolved image, and some of the very fine spatial features that are not shown in the original images appear in the super-resolved Chl-a imageries. The networks are also applied to four other coastal and inland water regions. The results show that super-resolution occurs mainly on pixels of Chl-a and Kd(490) features, especially on the feature edges and locations with a large spatial gradient. The biases between the original M-band images and super-resolved high-resolution images are small for both Chl-a and Kd(490) in moderately to extremely turbid coastal oceans and inland waters, indicating that the super-resolution process does not change the mean values of the original images.

scholarly journals ZnWO4 Nanoparticle Scintillators for High Resolution X-ray Imaging

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1721
Author(s):  
Heon Yong Jeong ◽  
Hyung San Lim ◽  
Ju Hyuk Lee ◽  
Jun Heo ◽  
Hyun Nam Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
High Resolution ◽  
Tungsten Oxide ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
Average Size ◽  
And Tungsten

The effect of scintillator particle size on high-resolution X-ray imaging was studied using zinc tungstate (ZnWO4) particles. The ZnWO4 particles were fabricated through a solid-state reaction between zinc oxide and tungsten oxide at various temperatures, producing particles with average sizes of 176.4 nm, 626.7 nm, and 2.127 μm; the zinc oxide and tungsten oxide were created using anodization. The spatial resolutions of high-resolution X-ray images, obtained from utilizing the fabricated particles, were determined: particles with the average size of 176.4 nm produced the highest spatial resolution. The results demonstrate that high spatial resolution can be obtained from ZnWO4 nanoparticle scintillators that minimize optical diffusion by having a particle size that is smaller than the emission wavelength.

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