scholarly journals Spatial Resolutions of On-Axis and Off-Axis Transmission Kikuchi Diffraction Methods

2019 ◽  
Vol 9 (21) ◽  
pp. 4478 ◽  
Author(s):  
Yitian Shen ◽  
Jingchao Xu ◽  
Yongsheng Zhang ◽  
Yongzhe Wang ◽  
Jimei Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Electron Microscope ◽  
Spatial Resolution ◽  
Correlation Coefficients ◽  
Sample Thickness ◽  
Phase Identification ◽  
Specimen Thickness ◽  
Key Factors ◽  
Orientation Microscopy ◽  
Scanning Electron

Spatial resolution is one of the key factors in orientation microscopy, as it determines the accuracy of grain size investigation and phase identification. We determined the spatial resolutions of on-axis and off-axis transmission Kikuchi diffraction (TKD) methods by calculating correlation coefficients using only the effective parts of on-axis and off-axis transmission Kikuchi patterns. During the calculation, we used average filtering to evaluate the spatial resolution more accurately. The spatial resolutions of both on-axis and off-axis TKD methods were determined in the same scanning electron microscope at different accelerating voltages and specimen thicknesses. The spatial resolution of the on-axis TKD was higher than that of the off-axis TKD at the same parameters. Furthermore, with an increase in accelerating voltage or a decrease in specimen thickness, the spatial resolutions of the two configurations could be significantly improved, from tens of nanometers to below 10 nm. At a voltage of 30 kV and sample thickness of 74 nm, both on-axis and off-axis TKD methods exhibited the highest resolutions of 6.2 and 9.7 nm, respectively.

Resolution of a Transmitted Electron Image Formed by A Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 386-387
Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Image ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.

High-Spatial-Resolution Cathodoluminescence Measurement of InGaN

2002 ◽  
Vol 743 ◽  
Author(s):  
Hisashi Kanie ◽  
Hiroaki Okado ◽  
Takaya Yoshimura
Keyword(s):  
Electron Microscope ◽  
Energy Level ◽  
Spatial Resolution ◽  
Diffusion Length ◽  
High Spatial Resolution ◽  
Lower State ◽  
Measuring Apparatus ◽  
Bulk Crystals ◽  
Recombination Centers ◽  
Scanning Electron

ABSTRACTThis paper described observation of cathodoluminescence (CL) of microcrystalline InGaN bulk crystals under a scanning electron microscope (SEM) with a high-spatial-resolution (HR) CL measuring apparatus. HR-CL spectra from facets of InGaN crystals vary from facet to facet and are single peaked. Histogram analysis of the CL peak positions of HR spectra from the facets of the crystals in the area scanned during a low-resolution CL measurement shows a two-peaked form with comparable peak wavelengths. The diffusion length of a generated electron- ho le pair or an exciton from the recombination centers with a higher-energy-level state to that with a lower state is estimated to be 500 nm at the longest by the comparison of two monochromatic HR-CL images of adjoining facets.

Sintering Process of Nd:YAG Transparent Ceramic

2013 ◽  
Vol 281 ◽  
pp. 475-479
Author(s):  
Bo Wang ◽  
Quan Xi Cao ◽  
Guang Xu ◽  
Sen Tian
Keyword(s):  
Grain Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Crystal Structures ◽  
Heating Rate ◽  
Optical Transmittance ◽  
Sintering Process ◽  
X Ray ◽  
Polycrystalline Ceramics ◽  
Scanning Electron

1.0at% Nd:YAG polycrystalline ceramics were sintered at 1420°C, 1500°C, 1600°C and 1730°C respectively by different heating rate (1°C/min and 5°C/min). The crystal structures were indexed by X-ray diffractometer (XRD). The microstructure and the grain size of the samples were characterized by scanning electron microscope (SEM). The optical transmittance spectra of the samples were measured using V-570 UV spectrophotometer. The sintering process of Nd:YAG ceramics and the effect of heating rate on the microstructure of samples have been investigated.

scholarly journals Spatial Resolution in ACOM - What Will Come After EBSD

2008 ◽  
Vol 16 (1) ◽  
pp. 34-37 ◽  
Author(s):  
R.A. Schwarzer
Keyword(s):  
Grain Boundaries ◽  
Spatial Resolution ◽  
Crystal Orientation ◽  
High Sensitivity ◽  
Polycrystalline Materials ◽  
Phase Identification ◽  
Specific Level ◽  
Orientation Microscopy ◽  
Orientation Contrast ◽  
Phase Discrimination

Automated Crystal Orientation Microscopy (ACOM) on a grain specific level has proved to be an invaluable new tool for characterizing polycrystalline materials. It is usually based on scanning facilities using electron diffraction , due to its high sensitivity and spatial resolution, but also attempts have been made which rely upon X-ray or hard synchrotron radiation diffraction. The grain orientations are commonly mapped in pseudo-colors on the scanning grid to construct Crystal Orientation Maps (COM), which represent “images” of the microstructure with the advantage of providing quantitative orientation contrast. In a similar way, misorientations across grain boundaries, Σ values of grain boundaries, or other microstructural characteristics are visualized by mapping the grains in the micrograph with specific colors. The principal objectives are the determination of quantitative, statistically meaningful data sets of crystal orientations, misorientations, the CSL character (Σ) of grain boundaries, local crystal texture (pole figures, ODF, MODF, OCF) and derived entities, phase discrimination and phase identification.

Study on the Properties of Doped La in BaBi4Ti4O15 Ceramic

2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sintering Temperature ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lanthanum Content ◽  
Scanning Electron

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.

Effect of Different Abrasives on Chemical Mechanical Polishing for Magnesia Alumina Spinel

2020 ◽  
Vol 866 ◽  
pp. 115-124
Author(s):  
Zhan Kui Wang ◽  
Ming Hua Pang ◽  
Jian Xiu Su ◽  
Jian Guo Yao
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chemical Mechanical Polishing ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Key Factors ◽  
Particle Size Analyzer ◽  
Scanning Electron ◽  
Shape And Size

In this paper, a series of chemical mechanical polishing (CMP) experiments for magnesia alumina (Mg-Al) spinel were carried out with different abrasives, and the materials removal rate (MRR) and surface quality was evaluated to explore their different effects. The scanning electron microscope (SEM) and laser particle size analyzer were also employed to test the micro-shape and size distribution of abrasives. Then, the mechanism of different effects with different abrasives was analyzed in CMP for Mg-Al spinel. Those experimental results suggest that different subjecting pressure ratios of abrasives to polishing pad with different abrasive are the key factors leading to difference polishing performances in CMP.

High-Speed Orientation Microscopy with Offline Solving Sequences of EBSD Patterns

2010 ◽  
Vol 160 ◽  
pp. 295-300 ◽  
Author(s):  
Robert A. Schwarzer ◽  
Jarle Hjelen
Keyword(s):  
Quality Control ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
Orientation Microscopy ◽  
Fast Acquisition ◽  
Scanning Electron

A high speed in acquisition of backscatter Kikuchi patterns (BKP) and solving the stored raw patterns offline has many advantages over online EBSD. No compromise is made between speed and reliability. Automated backscatter Kikuchi diffraction in the scanning electron microscope (SEM) is about to become a tool for process and quality control. Mandatory requirements for these applications are measures to enable re-examination of the results at any time and a high speed. Therefore, fast acquisition of pattern sequences and off¬line indexing will soon become standard. Online pattern solving is optional, but at the disadvantage of reduced speed and reliability.

Microdiffraction phase identification in the scanning electron microscope (SEM)

2004 ◽  
Vol 19 (2) ◽  
pp. 100-103 ◽  
Author(s):  
R. P. Goehner ◽  
J. R. Michael
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Beam Current ◽  
Electron Diffraction Data ◽  
Specimen Preparation ◽  
Phase Identification ◽  
Electron Backscattered Diffraction ◽  
Backscattered Electron ◽  
Ccd Detectors ◽  
Scanning Electron

The identification of crystallographic phases in the scanning electron microscope (SEM) has been limited by the lack of a simple way to obtain electron diffraction data of an unknown while observing the microstructure of the specimen. With the development of charge coupled device (CCD)-based detectors, backscattered electron Kikuchi patterns, alternately referred to as electron backscattered diffraction (EBSD) patterns, can be easily collected. Previously, EBSD has been limited to crystallographic orientation studies due to the poor pattern quality collected with video rate detector systems. With CCD detectors, a typical EBSD can now be acquired from a micron or submicron sized crystal using an exposure time of 1–10 s with an accelerating voltage of 10–40 kV and a beam current as low as 0.1 nA. Crystallographic phase analysis using EBSD is unique in that the properly equipped SEM permits high magnification images, EBSDs, and elemental information to be collected from bulk specimens. EBSD in the SEM has numerous advantages over other electron beam-based crystallographic techniques. The large angular view (∼70°) provided by EBSD and the ease of specimen preparation are distinct advantages of the technique. No sample preparation beyond what is commonly used for SEM specimens is required for EBSD.

In Situ Scanning Electron Microscopy Observation of the Pattern Formation on the Surface of Al/Ge Bilayer Films

2007 ◽  
Vol 539-543 ◽  
pp. 3568-3573
Author(s):  
H. Kumagai ◽  
M. Shibata ◽  
Tomokazu Moritani ◽  
Takao Kozakai ◽  
Minoru Doi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Free Surface ◽  
Electron Microscope ◽  
Microscopy Observation ◽  
Bilayer Films ◽  
Fractal Patterns ◽  
Scanning Electron

When the Al/Ge/SiO2 bilayer films are annealed in-situ in a scanning electron microscope (SEM) at the temperatures lower than the crystallization temperature of amorphous Ge itself, the so-called metal-mediated-crystallization (MMC) takes place. In the course of MMC, crystalline Ge aggregates (Ge clusters) form in the bilayer films, which results in the formation and the evolution of impressive fractal patterns with branching on the free surface. In-situ SEM observations of annealed Al/Ge/SiO2 bilayer films indicate that the grain size of polycrystalline Al-layer influences the nucleation of Ge clusters and hence of fractal patterns. For the bilayer films containing larger Al grains, the nucleation rate of fractal patterns (Ge clusters) is faster and the number of patterns is larger.

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