scholarly journals Manipulation of nanoparticles of different shapes inside a scanning electron microscope

2014 ◽  
Vol 5 ◽  
pp. 133-140 ◽  
Author(s):  
Boris Polyakov ◽  
Sergei Vlassov ◽  
Leonid M Dorogin ◽  
Jelena Butikova ◽  
Mikk Antsov ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tuning Fork ◽  
Quartz Tuning Fork ◽  
Static Friction ◽  
Si Substrate ◽  
Friction Forces ◽  
Different Shapes ◽  
Particle Geometry ◽  
Scanning Electron

In this work polyhedron-like gold and sphere-like silver nanoparticles (NPs) were manipulated on an oxidized Si substrate to study the dependence of the static friction and the contact area on the particle geometry. Measurements were performed inside a scanning electron microscope (SEM) that was equipped with a high-precision XYZ-nanomanipulator. To register the occurring forces a quartz tuning fork (QTF) with a glued sharp probe was used. Contact areas and static friction forces were calculated by using different models and compared with the experimentally measured force. The effect of NP morphology on the nanoscale friction is discussed.

Effect of SiO2 Thickness on GaAs Nanowires on Si (111) Substrates Grown by Molecular Beam Epitaxy

2015 ◽  
Vol 1131 ◽  
pp. 16-19
Author(s):  
Patchareewan Prongjit ◽  
Samatcha Vorathamrong ◽  
Somsak Panyakeow ◽  
Chiraporn Tongyam ◽  
Piyasan Prasertthdam ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Molecular Beam Epitaxy ◽  
Scanning Electron Microscope ◽  
Structural Properties ◽  
Molecular Beam ◽  
Molecular Beam Epitaxy Growth ◽  
Si Substrate ◽  
Growth Technique ◽  
Gaas Nanowires ◽  
Scanning Electron

The GaAs nanowires are grown on Si (111) substrates by Ga-assisted molecular beam epitaxy growth technique. The effect of SiO2 thickness on the structural properties of GaAs nanowires is investigated by Scanning Electron Microscope (SEM). The nucleation of GaAs nanowires related to the presence of a SiO2 layer previously coated on Si substrate. The results show that the density, length, and diameter of GaAs nanowires strongly depend on the oxidation time (or SiO2 thickness).

Controlling the Growth of ZnO-SiO2 Nanostructures Using Pt-Coated Si Substrate

2014 ◽  
Vol 548-549 ◽  
pp. 354-357 ◽  
Author(s):  
Amber Dea Marie V. Peguit ◽  
Rolando T. Candidato ◽  
Reynaldo M. Vequizo ◽  
Majvell Kay G. Odarve ◽  
Bianca Rae B. Sambo ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Active Sites ◽  
Zno Nanostructures ◽  
Si Substrate ◽  
X Ray ◽  
Si Substrates ◽  
Scanning Electron ◽  
Pronounced Peak

ZnO-SiO2 nanostructures were grown on both bare Si and Pt-coated Si substrates via chemical bath deposition (CBD). The grown nanostructures were characterized using Scanning Electron Microscope with Energy Dispersive X-ray Spectroscopy (SEM-EDS), Fourier Transform Infrared (FTIR) measurement and Ultraviolet-Visible (UV-Vis) absorption spectroscopy. Surface morphology results revealed that Pt-coated Si substrate have promoted the growth of ZnO-SiO2 nanostructures by providing more active sites for nucleation thus formation ZnO-SiO2 nanostructures were observed. It is believed that SiO2 will adhere to the non-polar sides of the grown ZnO nanostructures. This result is manifested in the FTIR spectra which showed a pronounced peak corresponding to ZnO-SiO2 grown on bare Si suggesting that more Si-O bonds are present. However, Pt-coating did not significantly affect the band gap of the grown ZnO-SiO2 nanostructures.

Redefinition of Denisiella Folsom & Mills, 1938 (Collembola: Sminthurididae) with description of three new species from Brazil

Zootaxa ◽  
2018 ◽  
Vol 4434 (1) ◽  
pp. 111
Author(s):  
JOSÉ G. PALACIOS-VARGAS ◽  
AILA SOARES FERREIRA ◽  
DOUGLAS ZEPPELINI
Keyword(s):  
Electron Microscope ◽  
New Species ◽  
Scanning Electron Microscope ◽  
Antennal Segment ◽  
Different Shapes ◽  
Three New Species ◽  
New Diagnosis ◽  
Scanning Electron ◽  
Shape And Size

A new diagnosis of Denisiella is provided, based on the revision of most descriptions, including three new species from Brazil. New Brazilian taxa share the presence of 6 + 6 eyes, 4 + 4 serrate spine-like on tibiotarsi III and the polycarinate setae on tibiotarsi II but differ from each other by the shape and size of the sensilla of the tibiotarsi I. Denisiella rhizophorae sp. nov. has the combination of sensilla on tibiotarsi I of rhagidial type and C2 blunt on antennal segment III. Only D. betschi sp. nov. has barbulate spines on head and D. caatingae sp. nov. is the only which males present nasal organ. They are illustrated with drawings and scanning electron microscope photographs. Three different shapes of sensilla in the tibiotarsi I were observed and were compared with other species. 

Effect of Crystal Orientation Agents on Morphology of Nano-CaCO3

2015 ◽  
Vol 723 ◽  
pp. 544-547
Author(s):  
Xiang Wei Cheng ◽  
Da Jin Xiong ◽  
Chao Huo
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Crystal Orientation ◽  
Average Particle ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Calcite Crystal ◽  
X Ray ◽  
Different Shapes ◽  
Scanning Electron

Using intermittent bubbling carbonation method to prepare nanoCaCO3, the effect of crystal orientation agents on the morphology of nanoCaCO3 was studied. The nanoCaCO3 was characterized by means of field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), Laser particle analyzer. The results showed that the different shapes nanoCaCO3 was synthesized by adding different crystal orientation agents to control the shape of the product. The as-prepared CaCO3 were pure calcite crystal and the average particle sizes were within the range of 25.7 to 60.9 nm.

scholarly journals Twisting of Fibers Balancing the Gel–Sol Transition in Cellulose Aqueous Suspensions

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 873 ◽  
Author(s):  
Dmitry Zlenko ◽  
Sergey Nikolsky ◽  
Alexander Vedenkin ◽  
Galina Politenkova ◽  
Aleksey Skoblin ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cellulose Fibers ◽  
Film Production ◽  
3D Scaffold ◽  
Friction Forces ◽  
Practical Applications ◽  
Exponential Increase ◽  
The Individual ◽  
Scanning Electron

Cellulose hydrogels and films are advantageous materials that are applied in modern industry and medicine. Cellulose hydrogels have a stable scaffold and never form films upon drying, while viscous cellulose hydrosols are liquids that could be used for film production. So, stabilizing either a gel or sol state in cellulose suspensions is a worthwhile challenge, significant for the practical applications. However, there is no theory describing the cellulose fibers’ behavior and processes underlying cellulose-gel-scaffold stabilizing. In this work, we provide a phenomenological mechanism explaining the transition between the stable-gel and shapeless-sol states in a cellulose suspension. We suppose that cellulose macromolecules and nanofibrils under strong dispersing treatment (such as sonication) partially untwist and dissociate, and then reassemble in a 3D scaffold having the individual elements twisted in the nodes. The latter leads to an exponential increase in friction forces between the fibers and to the corresponding fastening of the scaffold. We confirm our theory by the data on the circular dichroism of the cellulose suspensions, as well as by the direct scanning electron microscope (SEM) observations and theoretical assessments.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

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.

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