scholarly journals Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Thomas Kowoll ◽  
Erich Müller ◽  
Susanne Fritsch-Decker ◽  
Simon Hettler ◽  
Heike Störmer ◽  
...  
Keyword(s):  
Experimental Data ◽  
Indium Tin Oxide ◽  
Complex Structure ◽  
Quantitative Agreement ◽  
Primary Electron ◽  
Sem Images ◽  
Backscattered Electron ◽  
Material Contrast ◽  
Optimum Material ◽  
Working Distance

This study is concerned with backscattered electron scanning electron microscopy (BSE SEM) contrast of complex nanoscaled samples which consist of SiO2 nanoparticles (NPs) deposited on indium-tin-oxide covered bulk SiO2 and glassy carbon substrates. BSE SEM contrast of NPs is studied as function of the primary electron energy and working distance. Contrast inversions are observed which prevent intuitive interpretation of NP contrast in terms of material contrast. Experimental data is quantitatively compared with Monte-Carlo- (MC-) simulations. Quantitative agreement between experimental data and MC-simulations is obtained if the transmission characteristics of the annular semiconductor detector are taken into account. MC-simulations facilitate the understanding of NP contrast inversions and are helpful to derive conditions for optimum material and topography contrast.

scholarly journals Investigation of the Effect of Magnification, Accelerating Voltage, and Working Distance on the 3D Digital Reconstruction Techniques

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Seyed Mahmoud Bayazid ◽  
Nicolas Brodusch ◽  
Raynald Gauvin ◽  
Michela Relucenti
Keyword(s):  
Spherical Particles ◽  
Reconstruction Technique ◽  
Quantitative Characterization ◽  
Sem Images ◽  
Digital Reconstruction ◽  
Backscattered Electron ◽  
Working Distance ◽  
Backscattered Signals ◽  
2D Images

In this study, the effect of Scanning Electron Microscopy (SEM) parameters such as magnification ( M ), accelerating voltage ( V ), and working distance (WD) on the 3D digital reconstruction technique, as the first step of the quantitative characterization of fracture surfaces with SEM, was investigated. The 2D images were taken via a 4-Quadrant Backscattered Electron (4Q-BSE) detector. In this study, spherical particles of Ti-6Al-4V (15-45 μm) deposited on the silicon substrate were used. It was observed that the working distance has a significant influence on the 3D digital rebuilding method via SEM images. The results showed that the best range of the working distance for our system is 9 to 10 mm. It was shown that by increasing the magnification to 1000x, the 3D digital reconstruction results improved. However, there was no significant improvement by increasing the magnification beyond 1000x. In addition, results demonstrated that the lower the accelerating voltage, the higher the precision of the 3D reconstruction technique, as long as there are clean backscattered signals. The optimal condition was achieved when magnification, accelerating voltage, and working distance were chosen as 1000x, 3 kV, and 9 mm, respectively.

Application of Monte Carlo Simulation Method to the Nano-Scale Characterization by Scanning Electron Microscopy

2005 ◽  
Vol 475-479 ◽  
pp. 4161-4164
Author(s):  
Z.J. Ding ◽  
H.M. Li ◽  
X. Sun
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Complex Structure ◽  
Simulation Method ◽  
Step Length ◽  
Primary Electron ◽  
Sem Images ◽  
Backscattered Electrons ◽  
Nano Scale ◽  
Scanning Electron

Topographic imaging of materials by a scanning electron microscope (SEM), using the secondary electrons and backscattered electrons escaped from the surface under a primary electron beam bombardment as image signals, has been a very important technique in application to material sciences and the related fields. In this work we have developed a new parallel Monte Carlo simulation program to calculate SEM images especially for an inhomogeneous sample with a complex structure, which may be constructed with some basic geometrical shapes containing different materials. The ray-tracing arithmetic is employed to obtain the corrected electron flight step length for electrons across the interface of different zones containing distinct elements. We have done simulations for several specimens with artificial structures at the nm level. The results illustrate some new characters of image contrast, demonstrating the applicability of this image simulation technique to the characterization of nano-scale structure.

Remarks on the application of backscattered electron imaging (BEI) to the scanning electron microscopy (SEM) of biological structures

1983 ◽  
Vol 41 ◽  
pp. 484-487
Author(s):  
Etienne de Harven
Keyword(s):  
High Resolution ◽  
Incident Beam ◽  
Spot Size ◽  
Primary Electron ◽  
Critical Point Drying ◽  
Cell Shapes ◽  
High Resolution Images ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
Scanning Electron

Biological ultrastructures have been extensively studied with the scanning electron microscope (SEM) for the past 12 years mainly because this instrument offers accurate and reproducible high resolution images of cell shapes, provided the cells are dried in ways which will spare them the damage which would be caused by air drying. This can be achieved by several techniques among which the critical point drying technique of T. Anderson has been, by far, the most reproducibly successful. Many biologists, however, have been interpreting SEM micrographs in terms of an exclusive secondary electron imaging (SEI) process in which the resolution is primarily limited by the spot size of the primary incident beam. in fact, this is not the case since it appears that high resolution, even on uncoated samples, is probably compromised by the emission of secondary electrons of much more complex origin.When an incident primary electron beam interacts with the surface of most biological samples, a large percentage of the electrons penetrate below the surface of the exposed cells.

Mosaic Mapping: A Means of Tiling Images to Shorten Acquisition Speed for Lower - Magnification SEM Images and Wavelength Dispersive Spectrometers (WDS) X-Ray Maps

1996 ◽  
Vol 54 ◽  
pp. 438-439
Author(s):  
J.D. Geller ◽  
C.R. Herrington
Keyword(s):  
Limiting Factors ◽  
X Rays ◽  
Angular Range ◽  
Acceptance Angle ◽  
Sem Images ◽  
Worst Case ◽  
X Ray ◽  
Focusing Distance ◽  
Layered Crystals ◽  
Working Distance

The minimum magnification for which an image can be acquired is determined by the design and implementation of the electron optical column and the scanning and display electronics. It is also a function of the working distance and, possibly, the accelerating voltage. For secondary and backscattered electron images there are usually no other limiting factors. However, for x-ray maps there are further considerations. The energy-dispersive x-ray spectrometers (EDS) have a much larger solid angle of detection that for WDS. They also do not suffer from Bragg’s Law focusing effects which limit the angular range and focusing distance from the diffracting crystal. In practical terms EDS maps can be acquired at the lowest magnification of the SEM, assuming the collimator does not cutoff the x-ray signal. For WDS the focusing properties of the crystal limits the angular range of acceptance of the incident x-radiation. The range is dependent upon the 2d spacing of the crystal, with the acceptance angle increasing with 2d spacing. The natural line width of the x-ray also plays a role. For the metal layered crystals used to diffract soft x-rays, such as Be - O, the minimum magnification is approximately 100X. In the worst case, for the LEF crystal which diffracts Ti - Zn, ˜1000X is the minimum.

A New Dynamic Wettability-Alteration Model for Oil-Wet Cores During Surfactant-Solution Imbibition

SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 818-828 ◽  
Author(s):  
M. Hosein Kalaei ◽  
Don W. Green ◽  
G. Paul Willhite
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
History Matching ◽  
Mechanistic Model ◽  
Surfactant Solution ◽  
Experimental Tests ◽  
Quantitative Agreement ◽  
Wettability Alteration ◽  
Porous Rock ◽  
Surfactant Solutions

Summary Wettability modification of solid rocks with surfactants is an important process and has the potential to recover oil from reservoirs. When wettability is altered by use of surfactant solutions, capillary pressure, relative permeabilities, and residual oil saturations change wherever the porous rock is contacted by the surfactant. In this study, a mechanistic model is described in which wettability alteration is simulated by a new empirical correlation of the contact angle with surfactant concentration developed from experimental data. This model was tested against results from experimental tests in which oil was displaced from oil-wet cores by imbibition of surfactant solutions. Quantitative agreement between the simulation results of oil displacement and experimental data from the literature was obtained. Simulation of the imbibition of surfactant solution in laboratory-scale cores with the new model demonstrated that wettability alteration is a dynamic process, which plays a significant role in history matching and prediction of oil recovery from oil-wet porous media. In these simulations, the gravity force was the primary cause of the surfactant-solution invasion of the core that changed the rock wettability toward a less oil-wet state.

scholarly journals EXPLORATION OF INTERCALATED KAOLINITE CLAY FOR THE UPTAKE OF BASIC DYE BY ADSORPTION − EQUILIBRIUM, KINETICS AND THERMODYNAMIC STUDIES

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
C. E. Chigbundu ◽  
K. O. Adebowale
Keyword(s):  
Experimental Data ◽  
Linear Regression ◽  
Goodness Of Fit ◽  
Linear Regression Analysis ◽  
Dye Adsorption ◽  
Batch Adsorption ◽  
Sem Images ◽  
Kaolinite Clay ◽  
Non Linear ◽  
The Impact

Dyes are complex and sensitive organic chemicals which exposes microbial populations, aquatic lives and other living organisms to its toxic effects if their presence in water bodies or industrial effluents are not properly handled. This work therefore, comparatively studied the adsorption efficiencies of natural raw kaolinite (NRK) clay adsorbent and dimethyl sulphoxide (DMSO) faciley intercalated kaolinite clay (DIK) adsorbent for batch adsorption of Basis Red 2 (BR2) dye. The impact of varying the contact time, temperature and other operating variables on adsorption was also considered. The two adsorbents were characterized using SEM images, FTIR and XRD patterns. Linear and non-linear regression analysis of different isotherm and kinetic models were used to describe the appropriate fits to the experimental data. Error analysis equations were also used to measure the goodness-of-fit. Langmuir isotherm model best described the adsorption as being monolayer on homogenous surfaces while Kinetic studies showed that Elovich model provides the best fit to experimental data. The adsorption capacities of NRK and DIK adsorbents for the uptake of BR2 were 16.30 mg/g and 32.81 mg/g, respectively (linear regression) and 19.30 mg/g and 30.81 mg/g, respectively (non-linear regression). The thermodynamic parameter, ∆G showed that BR2 dye adsorption onto the adsorbents were spontaneous. DIK adsorbent was twice efficient compared with NRK for the uptake of BR2 dye.

scholarly journals Influence of Monomer Concentration on the Morphologies and Electrochemical Properties of PEDOT, PANI, and PPy Prepared from Aqueous Solution

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Shalini Kulandaivalu ◽  
Zulkarnain Zainal ◽  
Yusran Sulaiman
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Monomer Concentration ◽  
Lithium Perchlorate ◽  
Sem Images ◽  
Eis Measurements ◽  
Scanning Electron

Poly(3,4-ethylenedioxyhiophene) (PEDOT), polyaniline (PANI), and polypyrrole (PPy) were prepared on indium tin oxide (ITO) substrate via potentiostatic from aqueous solutions containing monomer and lithium perchlorate. The concentration of monomers was varied between 1 and 10 mM. The effects of monomer concentration on the polymers formation were investigated and compared by using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements. FTIR and Raman spectra showed no changes in the peaks upon the increment of the concentration. Based on the SEM images, the increment in monomer concentration gives significant effect on morphologies and eventually affects the electrochemical properties. PEDOT electrodeposited from 10 mM solution showed excellent electrochemical properties with the highest specific capacitance value of 12.8 mF/cm2.

scholarly journals Force Dependence of Velocity and Run Length of Kinesin-1, Kinesin-2 and Kinesin-5 Family Molecular Motors

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 287 ◽  
Author(s):  
Si-Kao Guo ◽  
Wei-Chi Wang ◽  
Peng-Ye Wang ◽  
Ping Xie
Keyword(s):  
Experimental Data ◽  
Atpase Activity ◽  
Rate Constants ◽  
Molecular Motors ◽  
Quantitative Agreement ◽  
Run Length ◽  
Movement Dynamics ◽  
Proposed Model ◽  
Movement Mechanism ◽  
The Difference

Kinesin-1, kinesin-2 and kinesin-5 are three families of a superfamily of motor proteins; which can walk processively on microtubule filaments by hydrolyzing ATP. It was experimentally shown that while the three kinesin dimers show similar feature on the force dependence of velocity, they show rather different features on the force dependence of run length. However, why the three families of kinesins show these rather different features is unclear. Here, we computationally studied the movement dynamics of the three dimers based on our proposed model. The simulated results reproduce well the available experimental data on the force dependence of velocity and run length. Moreover, the simulated results on the velocity and run length for the three dimers with altered neck linker lengths are also in quantitative agreement with the available experimental data. The studies indicate that the three families of kinesins show much similar movement mechanism and the rather different features on the force dependence of run length arise mainly from the difference in rate constants of the ATPase activity and neck linker docking. Additionally, the asymmetric (limping) movement dynamics of the three families of homodimers with and without altered neck linker lengths are studied, providing predicted results.

Enhancement of image contrast for carbon nanotube and polymer composite film in scanning electron microscope

Microscopy ◽  
2020 ◽  
Vol 69 (3) ◽  
pp. 167-172
Author(s):  
Yoichiro Hashimoto ◽  
Hiroyuki Ito ◽  
Masahiro Sasajima
Keyword(s):  
Composite Film ◽  
Electron Beam Irradiation ◽  
Detection System ◽  
Energy Condition ◽  
Image Contrast ◽  
Energy Conditions ◽  
Beam Irradiation ◽  
Sem Images ◽  
Ptfe Composite ◽  
Backscattered Electron

Abstract Image contrast between carbon nanotubes (CNTs) and polytetrafluoroethylene (PTFE) in a CNT/PTFE composite film, which is difficult to obtain by conventional backscattered electron (BSE) imaging, was optimized to better elucidate the distribution of CNT in the film. Ultra-low landing energy condition (0.3 keV in this study) was used to prevent specimen damage due to electron beam irradiation. Signal acceptance maps, which represent the distributions of energy and take-off angle, were calculated to evaluate the features of the signal detection system used in this study. SEM images of this composite film were taken under several sets of conditions and analyzed using these acceptance maps. CNT and PTFE in the composite film can be clearly distinguished with material and topographic contrasts using the BSE signal under optimized energy and take-off angle ranges, even at ultra-low landing energy conditions.

scholarly journals True Colour SEM Imaging for Phase Recognition AMD X-Ray Microanalysis

1997 ◽  
Vol 5 (3) ◽  
pp. 8-18
Author(s):  
Peter J. Statham
Keyword(s):  
Signal Strength ◽  
Elemental Content ◽  
Data Manipulation ◽  
X Ray ◽  
Large Numbers ◽  
Backscattered Electron ◽  
Material Contrast ◽  
Sem Imaging ◽  
Phase Recognition ◽  
False Colour

Secondary (SE) and backscattered electron (BSE) signals in the SEM provide high resolution monochrome images. BSE signal strength is modulated by mean atomic number and ‘false” colour can be introduced to enhance material contrast. Colour can also be introduced using multiple SE detectors, each with a different sensitivity to topographic and compositional information: by controlling signal mixtures and colours, the operator effectively has access to a powerful “studio” to generate aesthetically pleasing colour images. In both these examples, the correspondence between local elemental content and colour is entirely arbitrary and under subjective control of the operator, Elemental x-ray maps can be acquired and combinations colour coded to reveal phase distributions. For large numbers of maps and images, chemometric techniques such as PCA may be used to discover common relationships and assist the process of colour coding. Images derived from x-ray maps are usually low resolution and the analyst has to decide which elements to include and do a fair amount of data manipulation before any conclusions can be drawn.

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