Single-crystalline Tungsten Nanoparticles Produced by Thermal Decomposition of Tungsten Hexacarbonyl

2000 ◽  
Vol 15 (7) ◽  
pp. 1564-1569 ◽  
Author(s):  
Martin H. Magnusson ◽  
Knut Deppert ◽  
Jan-Olle Malm
Keyword(s):  
Thermal Decomposition ◽  
Semiconductor Device ◽  
Particle Morphology ◽  
Sintering Behavior ◽  
Tungsten Hexacarbonyl ◽  
Single Crystalline ◽  
Ambient Temperatures ◽  
Transmission Electron ◽  
Charging Mechanism ◽  
Tungsten Nanoparticles

Nanometer-sized particles of W are of interest in semiconductor device research, where such particles may store electrons inside heteroepitaxially defined structures. In this paper, we present results concerning W particles produced by thermal decomposition of tungsten hexacarbonyl. By the described method, it was possible to produce size-selected, single-crystalline W particles in the size range between 15 and 60 nm. The sintering behavior of the particles was studied between ambient temperatures and 1900 °C. The particle morphology and structure were examined with high-resolution transmission electron microscopy and electron diffraction techniques. Particles sintered at the highest temperatures typically were single crystals, with well-developed facets. Some problems concerning a yield reducing charging mechanism are discussed.

Cryomicroscopy of multiphase latices

1991 ◽  
Vol 49 ◽  
pp. 1060-1061
Author(s):  
O. L. Shaffer ◽  
M.S. El-Aasser ◽  
C. L. Zhao ◽  
M. A. Winnik ◽  
R. R. Shivers
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Freeze Fracture ◽  
Particle Morphology ◽  
Second Stage ◽  
Transmission Electron ◽  
Important Approach ◽  
Carbon Coated ◽  
Preparation Techniques

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

Development of High Accuracy Automatic Magnification Calibration Function for Scanning Transmission Electron Microscope

2005 ◽  
Author(s):  
Hiromi Inada ◽  
D. Terauchi ◽  
A. Takane ◽  
S. Aizawa ◽  
H. Tanaka ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Semiconductor Device ◽  
Gate Oxide ◽  
Scanning Transmission Electron Microscope ◽  
High Accuracy ◽  
Silicon Single Crystal ◽  
Calibration Function ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Transmission Microscope

Abstract In the field of semiconductor development and failure analysis, metrology of layers such as gate oxide layer is one of the important analysis due to determine semiconductor itself characteristics. The number of requirements of metrology is increasing by using both scanning and transmission electron microscopy. High accurate metrology depends on accuracy of magnification of electron microscope. We developed accurate magnification calibration for scanning transmission microscope. This method is carried out by using micro scale specimen and silicon single crystal lattice fringe images. We achieved absolute magnification error of less than 2% for all magnification. This microscope provides high accuracy metrology for semiconductor device. We describe an automatic magnification calibration function for the high magnification range required to accurately measure features from a few to tens of nm in size.

Effect of synthesis and activation methods on the character of CoMo/ultrastable Y-zeolite catalysts

2021 ◽  
Vol 19 (1) ◽  
pp. 745-754
Author(s):  
Khoirina Dwi Nugrahaningtyas ◽  
Eddy Heraldy ◽  
Rachmadani ◽  
Yuniawan Hidayat ◽  
Indriana Kartini
Keyword(s):  
Electron Microscopy ◽  
Reduction Process ◽  
Particle Morphology ◽  
Zeolite Catalysts ◽  
X Ray Diffraction ◽  
Y Zeolite ◽  
X Ray ◽  
Irregular Particle ◽  
Transmission Electron ◽  
Pure Metals

Abstract The properties of three types of CoMo/USY catalysts with different synthesized methods have been studied. The sequential and co-impregnation methods followed by activation using calcination and reduction process have been conducted. The properties of the catalysts were examined using Fourier-transform-infrared (FTIR) spectroscopy, X-ray diffraction (XRD) with refinement, and surface area analyzer (SAA). The FTIR spectrum study revealed the enhanced intensity of its Bronsted acid site, and the XRD diffractogram pattern verified the composition of pure metals, oxides, and alloys in the catalyst. The SAA demonstrated the mesoporous features of the catalyst. Scanning electron microscopy showed an irregular particle morphology. Additional analysis using the transmission electron microscopy indicated that the metal has successfully impregnated without damaging the USY structure.

scholarly journals A Facile Urea-Assisted Thermal Decomposition Process of TiO2 Nanoparticles and Their Photocatalytic Activity

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 165
Author(s):  
Sandip Madhukar Deshmukh ◽  
Mohaseen S. Tamboli ◽  
Hamid Shaikh ◽  
Santosh B. Babar ◽  
Dipak P. Hiwarale ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Photocatalytic Activity ◽  
Tio2 Nanoparticles ◽  
Large Scale ◽  
Ultra Violet ◽  
Tio2 Nps ◽  
Transmission Electron ◽  
Structures And Properties ◽  
Ft Ir ◽  
Large Scale Synthesis

In the present work, we have reported a facile and large-scale synthesis of TiO2 nanoparticles (NPs) through urea-assisted thermal decomposition of titanium oxysulphate. We have successfully synthesized TiO2 NPs by using this effective route with different weight ratios of titanium oxysulphate: urea. The structures and properties of TiO2 NPs were confirmed by scanning electron microscope) (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), ultra violet–visible spectroscopy (UV-vis), and photoluminescence (Pl) techniques. XRD demonstrated that TiO2 NPs holds of anatase crystal phase with crystallizing size 14–19 nm even after heating at 600 °C. TGA, SEM, and TEM images reveal urea’s role, which controls the size, morphology, and aggregation of TiO2 NPs during the thermal decomposition. These TiO2 NPs were employed for photodegradation of Methyl Orange (MO) in the presence of ultraviolet (UV) radiation. An interesting find was that the TiO2 NPs exhibited better photocatalytic activity and excellent recycling stability over several photodegradation cycles. Furthermore, the present method has a great perspective to be used as an efficient method for large-scale synthesis of TiO2 NPs.

Reduction of Selected Metal Oxides in a Thermal Plasma Produced by a Nontransferred ARC Torch

1987 ◽  
Vol 98 ◽  
Author(s):  
Brent A. Detering ◽  
James A. Batdorf ◽  
Chien M. Wai
Keyword(s):  
Thermal Decomposition ◽  
Fourier Transform ◽  
Flow Field ◽  
Emission Spectroscopy ◽  
Plasma Plume ◽  
Particle Morphology ◽  
Arc Plasma ◽  
Plasma Arc ◽  
Transform Method ◽  
Oxide Particles

ABSTRACTPlasma flow field temperatures are determined in a nontransferred arc plasma using emission spectroscopy. This technique is then utilized to identify thermal decomposition and reduction products produced in the plasma plume when metal oxide particles are injected into the plasma arc. The processed particles are then studied using AAS, SEM, EDS and XRD to characterize the chemical changes that have occurred in the particles. A Fourier transform method is used to study changes in particle morphology.

Single Variant Orientational Growth of Yba2Cu3O7-x on Vicinal (011) SrTiO3 Substrates.

1995 ◽  
Vol 401 ◽  
Author(s):  
A. L. Vasiliev ◽  
D. S. Linehan ◽  
E. P. Kvam ◽  
L. Hou ◽  
M. W. McElfresh
Keyword(s):  
Second Phase ◽  
Surface Cracks ◽  
Electron Microscopic ◽  
Ybco Films ◽  
Single Crystalline ◽  
X Ray ◽  
Transmission Electron ◽  
Transmission Electron Microscopic

AbstractThe results of a transmission electron microscopic (TEM) and X-ray microanalysis (EDS) study of Yba2Cu3O7-x (YBCO) films grown on vicinal (011) SrTiO3 substrates are presented. The YBCO films tend to be single crystalline grown in single variant orientation with c-axis =;45° from the surface. Cracks, second phase precipitates (CuO and Y2O3), and a few small YBCO grains in other orientations were revealed in the films.

Biological X-ray Microanalysis: The Past, Present Practices, and Future Prospects

2001 ◽  
Vol 7 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Patrick Echlin
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Transmission Electron Microscope ◽  
Low Voltage ◽  
High Energy ◽  
Scanning Transmission Electron Microscope ◽  
X Ray ◽  
Ambient Temperatures ◽  
Advantages And Disadvantages ◽  
Transmission Electron

Abstract A brief description is given of the events surrounding the development of biological X-ray microanalysis during the last 30 years, with particular emphasis on the contribution made by research workers in Cambridge, UK. There then follows a broad review of some applications of biological X-ray microanalysis. A more detailed consideration is given to the main thrust of current procedures and applications that are, for convenience, considered as four different kinds of samples. Thin frozen dried sections which are analyzed at ambient temperatures in a transmission electron microscope (TEM); semithin frozen dried sections which are analyzed at low temperature in a scanning transmission electron microscope (STEM); thick frozen hydrated sections which are analyzed at low temperature in a scanning electron microscope (SEM), and bulk samples which are analyzed at low temperature in the same type of instrument. A brief outline is given of the advantages and disadvantages of performing low-voltage, low-temperature X-ray microanalysis on frozen hydrated bulk biological material. The article concludes with a consideration of alternative approaches to in situ analysis using either high-energy beams or visible and near-visible photons.

scholarly journals Polypropylene Nanocomposites Obtained byIn SituPolymerization Using Metallocene Catalyst: Influence of the Nanoparticles on the Final Polymer Morphology

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Paula Zapata ◽  
Raúl Quijada
Keyword(s):  
Catalytic System ◽  
Sol Gel ◽  
Metallocene Catalyst ◽  
Particle Morphology ◽  
Polymer Particle ◽  
Silica Nanospheres ◽  
Sem Images ◽  
Transmission Electron ◽  
Polypropylene Nanocomposites

Polypropylene nanocomposites containing silica nanospheres based on the sol-gel methods were produced viain situpolymerization using a rac-Et(Ind)2ZrCl2/methylaluminoxane (MAO) system. Two different routes were used depending on the interaction between the silica nanoparticles with the catalytic system. In route 1 the nanoparticles were added together with the catalytic system (rac-Et(Ind)2ZrCl2)/(MAO) directly into the reactor, and in route 2 the metallocene rac-Et(Ind)2ZrCl2was supported on silica nanospheres pretreated with (MAO). SEM images show that when the nanospheres were added by both routes, they were replicated in the final polymer particle morphology; this phenomenon was more pronounced for PP obtained by route 2. The polypropylene (PP) nanocomposites obtained by both routes had a slightly higher percent crystallinities and crystallinity temperatures than pure PP. Transmission electron microscopy (TEM) images show that the nanospheres were well dispersed into the polypropylene matrix, particularly in the nanocomposites obtained by the support system (route 2).

EBIC and XTEM Analysis of High Voltage SMOS Reliability Failures

2002 ◽  
Vol 716 ◽  
Author(s):  
Larry Rice
Keyword(s):  
High Voltage ◽  
Focused Ion Beam ◽  
Semiconductor Device ◽  
Ion Beam ◽  
Electrical Characterization ◽  
Operating Conditions ◽  
Oxide Semiconductor ◽  
Power Transistors ◽  
Area Of Interest ◽  
Transmission Electron

AbstractMicroscopists are faced with many challenges in locating and examining failure sites in the ever-shrinking semiconductor device. The site must be located using electrical characterization techniques like electron beam induced current (EBIC), photo emission microscopy (PEM) or liquid crystal (LC) and then cross-sectioned with a focused ion beam (FIB). Both PEM and LC require the semiconductor circuit to be running near operating conditions which has been observed to locally melt the area of interest, frequently destroying evidence of the failure mechanism. In contrast, EBIC typically can be accomplished at low or no applied voltage eliminating further damage to the circuit. EBIC has been applied to locate leakage sites in high voltage metal oxide semiconductor (MOS) electro static discharge (ESD) reliability failures. In addition to a brief revisit of the basic principles of EBIC and describing a technique to successfully cross section ‘hot spots’ for transmission electron microscopy (TEM) observation, focus will be placed on a case study of the reliability testing failure analysis of ESD power transistors using EBIC, SEM, focused ion beam (FIB), and XTEM.

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