scholarly journals A Simple and “Green” Technique to Synthesize Metal Nanocolloids by Ultrashort Light Pulses

2020 ◽  
Author(s):  
Jesica María José Santillán ◽  
David Muñetón Arboleda ◽  
Valeria Beatriz Arce ◽  
Lucía Beatriz Scaffardi ◽  
Daniel Carlos Schinca
Keyword(s):  
Magnetic Behavior ◽  
Ultrashort Pulse Laser ◽  
Optical Extinction ◽  
Light Pulses ◽  
Transmission Electron ◽  
Ultrashort Light Pulses ◽  
The Stability ◽  
Green Technique ◽  
Compositional Properties

In this chapter Ag, Ni and Fe nanocolloids synthesized by “green” ultrashort pulse laser ablation of solid metal targets using different pulse energies and liquid media are characterized by different techniques. Optical extinction spectroscopy (OES), micro-Raman spectroscopy (MRS), transmission electron microscopy (TEM) and electron diffraction (ED) were independently used to analyze optical, morphological and compositional properties of the generated nanocolloids. In a deeper way, the stability characteristics of Ag nanocolloids in aqueous solutions with different stabilizers were studied owing to their potential use in biocompatible compounds. Besides, due to their interesting applications, few atoms Ag nanoclusters (NCs) were synthesized using the same ablation technique, analyzing their fluorescent and photocatalytic properties. On the other hand, to expand the characterization of the nanocolloids, their magnetic behavior was inspected for the Ni and Fe by vibrating sample magnetometry (VSM).

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

Structural Evolution Upon Annealing of Multi-Layer Si/Fe Thin Films Prepared by Magnetron Sputtering

2007 ◽  
Vol 561-565 ◽  
pp. 1161-1164
Author(s):  
Xiao Na Li ◽  
Bing Hu ◽  
Chuang Dong ◽  
Xin Jiang
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Room Temperature ◽  
Structural Evolution ◽  
Radio Frequency Magnetron Sputtering ◽  
Transmission Electron ◽  
Direct Band ◽  
The Stability ◽  
Sputtering System

Fe/Si multi-layer films were fabricated on Si (100) substrates utilizing radio frequency magnetron sputtering system. Si/β-FeSi2 structure was found in the films after the deposition. Structural characterization of Fe-silicide sample was performed by transmission electron microscopy, to explore the dependence of the microstructure of β-FeSi2 film on the preparation parameters. It was found that β-FeSi2 particles were formed after the deposition without annealing, whose size is less than 20nm ,with a direct band-gap of 0.94eV in room temperature. After annealing at 850°C, particles grow lager, however the stability of thin films was still good.

scholarly journals Microstructure Characterization of Welds in X5CrNiCuNb16-4 Steel in Overaged Condition

2019 ◽  
Vol 19 (1) ◽  
pp. 57-69
Author(s):  
A. Ziewiec ◽  
A. Zielińska-Lipiec ◽  
J. Kowalska ◽  
K. Ziewiec
Keyword(s):  
Electron Microscopy ◽  
Aging Time ◽  
Energy Dispersive Spectrometry ◽  
Solution Treatment ◽  
X Ray Diffraction ◽  
Density Distributions ◽  
Transmission Electron ◽  
Steel Welds ◽  
The Stability

AbstractThe paper presents the results of the investigation of microstructure of the welded X5CrNiCuNb16-4 (17-4PH) steel after solution treatment and aging at 620°C for different periods. The microstructure and the phase composition of the steel was investigated using light microscopy (LM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and the X-ray diffraction (XRD). Hardness was measured for samples aged at different times. Density distributions of Cu precipitates were established. The investigation has shown that the microstructure of the X5CrNiCuNb16-4 steel welds after aging at 620 ° C consists of tempered martensite, fine Cu precipitates and austenite. It was observed that the size of the Cu precipitates increases with increasing the aging time, what affects the decrease of hardness. Simultaneously, the quantity of reversed austenite increases with increase of aging time. It was revealed that enrichment of the austenite in Ni, Cu and C affects the increase of Ms, but this factor does not determine the stability of austenite.

Single-shot characterization of ultrashort light pulses

1991 ◽  
Vol 24 (8) ◽  
pp. 1225-1233 ◽  
Author(s):  
A Brun ◽  
P Georges ◽  
G Le Saux ◽  
F Salin
Keyword(s):  
Single Shot ◽  
Light Pulses ◽  
Ultrashort Light Pulses

scholarly journals Synthesis and characterization of ZnSe: Ag/SiO2 nanoparticles

2021 ◽  
Vol 261 ◽  
pp. 02063
Author(s):  
Fenghua Huang ◽  
Tao Huang ◽  
Xiangwei Wu ◽  
Wenhui Pang
Keyword(s):  
Visible Spectrum ◽  
Fluorescence Analysis ◽  
Sio2 Nanoparticles ◽  
Fluorescence Properties ◽  
Silicon Dioxide Nanoparticles ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Potential Applications ◽  
The Stability

Argentum-doped zinc selenide/silicon dioxide nanoparticles (expressed as ZnSe: Ag/SiO2) were synthesized by Stöber method. The structure, morphology and fluorescence properties of the quantum dots were characterized by X-ray powder diffraction, transmission electron microscopy, infrared spectrum, ultraviolet-visible spectrum and fluorescence spectrum. The results show that the as-prepared ZnSe: Ag/SiO2 nanoparticles are spherical, most of which are about 30 nm in size, and have good fluorescence properties. Compared with that of ZnSe: Ag nanoparticles, the stability of ZnSe: Ag/SiO2 nanoparticles is enhanced obviously. The ZnSe: Ag/SiO2 nanoparticles will have potential applications in biological fluorescence analysis.

Tem Structural Characterization of Nm-Scale Islands in Highly Mismatched Systems

1996 ◽  
Vol 421 ◽  
Author(s):  
S. Ruvimov ◽  
Z. Liliental-Weber ◽  
N.N. Ledentsov ◽  
M. Grundmann ◽  
D. Bimberg ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Growth Conditions ◽  
Island Size ◽  
Inas Quantum Dots ◽  
Growth Interruption ◽  
Transmission Electron ◽  
Theoretical Predictions ◽  
The Stability ◽  
Better Than

AbstractTransmission electron microscopy has been applied to study the ordering in size and shape of InAs quantum dots and in their lateral distribution. InAs islands were grown by MBE on GaAs substrates at different As-pressures and growth temperatures. Experiments with growth interupption support the theoretical predictions concerning equilibrium island size, shape and arrangement. The stability of the equilibrium dot arrays to changing of growth conditions was studied by varying the deposition temperature, arsenic pressure or growth interruption time. Significant deviation from the optimal As-pressure towards both the lower and higher values was shown to supress the formation of InAs dots resulting either in mesoscopic InAs clusters or 2D corrugated islands. Energy benefit due to the strain relaxation at island edges explains the experimental results better than kinetic consideration.

Structural and Magnetic Property Characterization of PY/CO Multilayer Films

Aerospace ◽  
2005 ◽  
Author(s):  
Priya David ◽  
E. I. Meletis
Keyword(s):  
Magnetic Properties ◽  
Magnetic Property ◽  
Magnetic Behavior ◽  
Multilayer Films ◽  
Si Substrate ◽  
Multilayered Films ◽  
Transmission Electron ◽  
Controlled Deposition ◽  
Constituent Elements

Multilayered films have emerged as an attractive choice of coating material in magnetic recording media and magneto-resistance device related applications. These films possess advantages such as excellent magnetic properties, good corrosion resistance and high chemical stability. Hence, it is imperative that their structural and magnetic properties be characterized so that they can be tailored for specific applications. The present study aims towards the development and characterization of Platinum (Pt)/Cobalt (Co) multilayer films for magnetic and structural properties. Pt/Co multilayered films were deposited on Silicon (Si) substrate using dual electron beam co-evaporation. Four layers of each Pt and Co were deposited on a Si substrate, forming a multilayer film. Controlled deposition rates were used in order to attain the desired thickness of Co and Pt layers. The films were characterized using scanning and transmission electron microscopy and surface profilometry. Magnetic property measurements were conducted on these films in both perpendicular and parallel orientations, in order to understand the correlation between structure of various constituent elements of the film and their magnetic behavior. Results are analyzed and compared with those obtained from previous studies on similar multilayer films, to gain a better understanding of the effect of various parameters on properties of the film.

scholarly journals Synthesis and Characterization of Copper Sulphide Nanoparticles in Aqueous Surfactant Solutions

1998 ◽  
Vol 16 (8) ◽  
pp. 667-677 ◽  
Author(s):  
Santosh K. Haram ◽  
Anand R. Mahadeshwar ◽  
Sharad G. Dixit
Keyword(s):  
Blue Shift ◽  
Copper Sulphide ◽  
X Ray ◽  
Surfactant Solutions ◽  
Transmission Electron ◽  
Ammonia Complex ◽  
Vis Spectroscopy ◽  
The Stability ◽  
Aqueous Micellar Solutions

Copper sulphide nanoparticles were synthesized by reacting a copper-ammonia complex with thiourea in aqueous micellar solutions of cationic, non-ionic and anionic surfactants. A blue shift in the absorption spectra revealed the formation of size-quantized nanoparticles. The influence of micelles in mediating the stabilization was studied by carrying out the reactions in surfactant solutions above and below the critical micelle concentration. The effect of thiourea on the stability of the nanoparticles was studied by synthesizing the nanoparticles at different mole ratios of reactants. Characterization of the nanoparticles was achieved by the use of transmission electron microscopy (TEM), X-ray powder diffraction (XRD), energy dispersive X-ray microanalysis (EDAX) and UV–vis spectroscopy.

scholarly journals Synthesis, characterization of Co1-xNixAl2O4 Spinel system and catalytic role in the synthesis of dihydropyrimidinone

2021 ◽  
Author(s):  
Teotone Vaz ◽  
Pranav P. Naik ◽  
Janesline Fernandes ◽  
Lalitprabha Salgaonkar ◽  
Snehal S. Hasolkar
Keyword(s):  
Fourier Transforms ◽  
Magnetic Behavior ◽  
Size Estimation ◽  
One Pot ◽  
Transmission Electron ◽  
Catalytic Role ◽  
The One ◽  
Co Precipitation ◽  
Citrate Precursor

Abstract In the present investigation, Spinel systems with chemical composition Co1 − xNixAl2O4 (x = 0.0, 0.25, 0.5, and 0.75) have been successfully synthesized by the co-precipitation citrate precursor technique. The phase formation, crystal structure, and impurity check were confirmed by X-ray powdered diffraction (XRD) and Fourier transforms infrared (FTIR) spectroscopy technique. The particle size estimation was done using a transmission electron microscope (TEM). Investigation of magnetic behavior and parameters such as saturation magnetization (MS), coercivity (HR), and retentivity (MR) was done using a vibrating sample magnetometer (VSM). The catalytic activity of prepared spinel systems was explored for the one-pot synthesis of dihydropyrimidinone derivatives. The catalytic product was identified by comparison of melting point and the spectral data (FTIR).

Sign in / Sign up

Export Citation Format

Share Document