scholarly journals Self-assembly of silicon nanowires studied by advanced transmission electron microscopy

2017 ◽  
Vol 8 ◽  
pp. 440-445 ◽  
Author(s):  
Marta Agati ◽  
Guillaume Amiard ◽  
Vincent Le Borgne ◽  
Paola Castrucci ◽  
Richard Dolbec ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Nanowires ◽  
Self Assembly ◽  
Inductively Coupled Plasma ◽  
Electron Tomography ◽  
Plasma Reactor ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Scanning Transmission

Scanning transmission electron microscopy (STEM) was successfully applied to the analysis of silicon nanowires (SiNWs) that were self-assembled during an inductively coupled plasma (ICP) process. The ICP-synthesized SiNWs were found to present a Si–SiO2 core–shell structure and length varying from ≈100 nm to 2–3 μm. The shorter SiNWs (maximum length ≈300 nm) were generally found to possess a nanoparticle at their tip. STEM energy dispersive X-ray (EDX) spectroscopy combined with electron tomography performed on these nanostructures revealed that they contain iron, clearly demonstrating that the short ICP-synthesized SiNWs grew via an iron-catalyzed vapor–liquid–solid (VLS) mechanism within the plasma reactor. Both the STEM tomography and STEM-EDX analysis contributed to gain further insight into the self-assembly process. In the long-term, this approach might be used to optimize the synthesis of VLS-grown SiNWs via ICP as a competitive technique to the well-established bottom-up approaches used for the production of thin SiNWs.

Three-Dimensional Imaging of Shear Band Produced by ECAP Process in Al-Ag Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 603-608
Author(s):  
Koji Inoke ◽  
Kenji Kaneko ◽  
Z. Horita
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Tomography ◽  
Shear Bands ◽  
Three Dimensional ◽  
Angular Pressing ◽  
Ecap Process ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Matrix

A significant change in microstructure occurs during the application of severe plastic deformation (SPD) such as by equal-channel angular pressing (ECAP). In this study, intense plastic strain was imposed on an Al-10.8wt%Ag alloy by the ECAP process. The amount of strain was controlled by the numbers of passes. After 1 pass of ECAP, shear bands became visible within the matrix. With increasing numbers of ECAP passes, the fraction of shear bands was increased. In this study, the change in microstructures was examined by three-dimensional electron tomography (3D-ET) in transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). With this 3D-ET method, it was possible to conduct a precise analysis of the sizes, widths and distributions of the shear bands produced by the ECAP process. It is demonstrated that the 3D-ET method is promising to understand mechanisms of microstructural refinement using the ECAP process.

scholarly journals Towards Reconfigurable Electronics: Silicidation of Top-Down Fabricated Silicon Nanowires

2019 ◽  
Vol 9 (17) ◽  
pp. 3462 ◽  
Author(s):  
Muhammad Bilal Khan ◽  
Dipjyoti Deb ◽  
Jochen Kerbusch ◽  
Florian Fuchs ◽  
Markus Löffler ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silicon Nanowires ◽  
Inductively Coupled Plasma ◽  
Density Functional ◽  
Field Effect Transistors ◽  
Density Functional Theory Calculations ◽  
Silicide Phase ◽  
Top Down ◽  
Inductively Coupled ◽  
Transmission Electron

We present results of our investigations on nickel silicidation of top-down fabricated silicon nanowires (SiNWs). Control over the silicidation process is important for the application of SiNWs in reconfigurable field-effect transistors. Silicidation is performed using a rapid thermal annealing process on the SiNWs fabricated by electron beam lithography and inductively-coupled plasma etching. The effects of variations in crystallographic orientations of SiNWs and different NW designs on the silicidation process are studied. Scanning electron microscopy and transmission electron microscopy are performed to study Ni diffusion, silicide phases, and silicide–silicon interfaces. Control over the silicide phase is achieved together with atomically sharp silicide–silicon interfaces. We find that {111} interfaces are predominantly formed, which are energetically most favorable according to density functional theory calculations. However, control over the silicide length remains a challenge.

Electron Tomography of HEK293T Cells Using Scanning Electron Microscope–Based Scanning Transmission Electron Microscopy

2012 ◽  
Vol 18 (5) ◽  
pp. 1037-1042 ◽  
Author(s):  
Yun-Wen You ◽  
Hsun-Yun Chang ◽  
Hua-Yang Liao ◽  
Wei-Lun Kao ◽  
Guo-Ji Yen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scanning Transmission Electron Microscopy ◽  
Electron Tomography ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
3D Volume ◽  
Scanning Electron

AbstractBased on a scanning electron microscope operated at 30 kV with a homemade specimen holder and a multiangle solid-state detector behind the sample, low-kV scanning transmission electron microscopy (STEM) is presented with subsequent electron tomography for three-dimensional (3D) volume structure. Because of the low acceleration voltage, the stronger electron-atom scattering leads to a stronger contrast in the resulting image than standard TEM, especially for light elements. Furthermore, the low-kV STEM yields less radiation damage to the specimen, hence the structure can be preserved. In this work, two-dimensional STEM images of a 1-μm-thick cell section with projection angles between ±50° were collected, and the 3D volume structure was reconstructed using the simultaneous iterative reconstructive technique algorithm with the TomoJ plugin for ImageJ, which are both public domain software. Furthermore, the cross-sectional structure was obtained with the Volume Viewer plugin in ImageJ. Although the tilting angle is constrained and limits the resulting structural resolution, slicing the reconstructed volume generated the depth profile of the thick specimen with sufficient resolution to examine cellular uptake of Au nanoparticles, and the final position of these nanoparticles inside the cell was imaged.

TEM and STEM Electron Tomography Analysis of Amorphous Alloys CoP-CoNiP System

2012 ◽  
Vol 590 ◽  
pp. 9-12 ◽  
Author(s):  
Tamara Mekhantseva ◽  
Oleg Voitenko ◽  
Ilya Smirnov ◽  
Evgeny Pustovalov ◽  
Vladimir Plotnikov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Amorphous Alloys ◽  
Electron Tomography ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
High Resolution Images ◽  
Electron Energy Loss ◽  
Tomography Analysis

This paper covers the analysis of amorphous alloys CoP-CoNiP system by means of high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy and electron tomography. The last years have seen a sufficient progress in the analysis of nanomaterials structure with the help of high resolution tomography. This progress was motivated by the development of microscopes equipped with aberration correctors and specialized sample holders which allow reaching the tilts angles up to ±80°. The opportunities delivered by the method of electron tomography sufficiently grow when producing high resolution images and using chemical analysis, such as X-Ray energy-dispersive microanalysis and electron energy loss spectroscopy (EELS).

Analysis of Pt-Nanoparticles Embedded on Crystalline TiO2 Studied by Transmission Electron Microscopy

2000 ◽  
Vol 638 ◽  
Author(s):  
Jordi Arbiol ◽  
Ana Ruiz ◽  
Albert Cirera ◽  
Francisca Peiró ◽  
Albert Cornet ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Inductively Coupled Plasma ◽  
Surface Density ◽  
Reaction Rate ◽  
Gas Sensing ◽  
Pt Nanoparticles ◽  
Inductively Coupled ◽  
Transmission Electron

AbstractIn this work, we studied the Pt particles embedded on crystalline TiO2 nanopowders. As it is well known, metal nanoparticles distributed on TiO2 surface can improve dramatically the reaction rate and selectivity of reaction in gas sensing. We prepared a wide set of TiO2 samples with different nominal Pt concentration. The aim of this study was to analyse the Pt distribution on TiO2 surface (density of Pt, particle size distribution, etc.), as well as the Pt phases existing in our samples. We used High Resolution Transmission Electron Microscopy (HRTEM) as a powerful tool to study Pt particles morphology. The HRTEM images were compared with computer simulations to confirm the results obtained. The chemical composition of the material has been also investigated by Inductively Coupled Plasma (ICP).

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