scholarly journals STRUCTURAL CHANGES IN PULSED LASER ABLATED CuInSe2 COMPOUND STRUKTURĀLĀS IZMAIŅAS IMPULSA LĀZERA ABLĒTAJĀ CuInSe2 SAVIENOJUMĀ

2013 ◽  
Vol 50 (6) ◽  
pp. 54-60
Author(s):  
A. Ogurcovs ◽  
V. Gerbreders ◽  
E. Tamanis ◽  
E. Sledevskis ◽  
A. Gerbreders
Keyword(s):  
Particle Size ◽  
Structural Changes ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Xrd Analysis ◽  
Spherical Particles ◽  
Nonlinear Relationship ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Average Size

Abstract CuInSe2 (CISe) compound was produced by high-temperature synthesis. After mechanical milling, the average CISe particle size decreased to 10μm. The authors study structural changes of the compound after ablation in liquid by a 1064 nm pulsed laser. The SEM examination indicated the presence of spherical particles with the average size of ~ 450 nm. A nonlinear relationship was established between the laser radiation dose and the quantity of spherical particles. The XRD analysis has shown an improvement in the CISe crystalline structure and the absence of significant changes in its stoichiometry. The 3 μm thick experimental CISe samples were screen-printed on planar Ni electrodes, and improvement also was revealed in their photosensitivity. The conclusion is that the pulsed-laser ablation can be applied to chalcopyrite structures like CISe without destruction of their initial properties.

Self-propagating high-temperature synthesis of the SiC

1986 ◽  
Vol 1 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Osamu Yamada ◽  
Yoshinari Miyamoto ◽  
Mitsue Koizumi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Exothermic Reaction ◽  
Experimental System ◽  
Ignition Process ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Effect Of Particle Size ◽  
Constituent Elements ◽  
Heat Released

Self-propagating high-temperature synthesis (SHS), also called combustion synthesis, is useful for fabricating numerous ceramics. In the case of SiC, heat released from the exothermic reaction is not sufficient to completely convert the mixed reactants of constituent elements into SiC in the usual nonadiabatic experimental system. This disadvantage could be overcome by a new ignition process called, the “direct passing method of electric current.” By using this method, stoichiometric fine SiC powder could be obtained rapidly and efficiently with low electric power. This paper also involves the effect of particle size of Si and C initial reactant powders on conversion efficiency into SiC and also on particle size of SiC powder fabricated by this method.

The average size of Si nanoparticles prepared by pulsed laser ablation in the gas mixture of He/Ar, Ne/Ar or He/Ne

2006 ◽  
Vol 515 (4) ◽  
pp. 1897-1900 ◽  
Author(s):  
Y.L. Wang ◽  
Z.C. Deng ◽  
G.S. Fu ◽  
Y. Zhou ◽  
L.Z. Chu ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Gas Mixture ◽  
Si Nanoparticles ◽  
Average Size

Room-temperature synthesis of submicron platinum and palladium powders in glycols

1999 ◽  
Vol 14 (9) ◽  
pp. 3707-3712 ◽  
Author(s):  
K. Tekaia-Elhsissen ◽  
F. Bonet ◽  
S. Grugeon ◽  
S. Lambert ◽  
R. Herrera-Urbina
Keyword(s):  
Size Distribution ◽  
Room Temperature ◽  
Spherical Particles ◽  
Average Particle ◽  
Particle Sizes ◽  
Temperature Synthesis ◽  
Bimodal Size Distribution ◽  
Hydrazine Reduction ◽  
Average Size ◽  
Palladium Particles

Platinum and palladium powders with average particle sizes in the submicron range have been synthesized at room temperature by hydrazine reduction of and , respectively, in glycols. Platinum powders contain spherical particles with a bimodal size distribution. Palladium powders also contain spherical particles, but the size distribution is narrow. The effect of both ammonia and hydrazine concentration on the size distribution and average size of palladium particles was investigated.

Quantum Confinement of GaAs Nanocrystals Deposited on PMMA Microspheres Using Pulsed Laser Ablation

2013 ◽  
Vol 660 ◽  
pp. 3-9
Author(s):  
Jeong Ho Ryu ◽  
Soon Yong Kweon ◽  
Jung Il Lee ◽  
Sung Lim Ryu
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser Deposition ◽  
Quantum Confinement ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Average Diameter ◽  
Laser Deposition ◽  
Spherical Particles ◽  
Novel Approach

A modified pulsed laser deposition (PLD) was employed to deposit GaAs nanocrystals on the surface of PMMA microspheres. This novel approach is distinguished by the fact that laser ablated materials are deposited uniformly onto the surface of spherical particles that are held constantly in a particle fludization unit. The XRD, SEM, EDX, TEM, EDP and PL results confirmed that cubic structured GaAs nanocrystals were deposited uniformly on the surface of PMMA microspheres with an average diameter of about 15 nm.

Preparation of Submicron Metastable Spherical β-Bi2O3 Particles by Self-Propagating High-Temperature Synthesis Method

2019 ◽  
Vol 19 (11) ◽  
pp. 7436-7441
Author(s):  
Chu Zhang ◽  
Qi-Yu Wang ◽  
Ming-De Li ◽  
Guo-Dong Zhang
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Synthesis Method ◽  
Reaction System ◽  
Average Diameter ◽  
Spherical Particles ◽  
Molar Ratio ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
One Step

Sub-micrometer particles of β-Bi2O3 were successfully synthesized via a one-step self-propagating high-temperature synthesis (SHS) method for the first time. The experiments were carried out in the air at room temperature. The products were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In this study, three experiments were designed to optimize the heat source, Bi source and additive for the reaction system. Results showed that the system composed of Al, Bi2O3 and Al2O3 powders could synthesize monodisperse high-purity β-Bi2O3 spherical particles with the average diameter of 369 nm and the as-prepared products kept stable after being exposed in air for one month. Then, the influences of the ratio of the three components on system were investigated. Interestingly, it was found that a slight adjustment on the ratio of Al:Bi2O3:Al2O3 had significant effects on the reactions happening in a system. Specifically, when the amount of Al2O3 exceeds the molar ratio of 2:1:1 (Al:Bi2O3:Al2O3), it is difficult to ignite the reaction system; when the amount is less than 2:1:0.5, the reaction system becomes too violent to obtain pure products. However, there are no obvious differences on the morphology and structure of final products with the two ratios because of few changes in adiabatic temperature. Preparation of β-Bi2O3 by SHS technique enjoying many advantages, such as high efficiency, inexpensive experimental equipment and simple processes, would has a promising prospect for industrial application.

СOLLOIDAL SYNTHESIS AND CHARACTERIZATION HYDROPHILIC CDTE QUANTUM DOTS FOR MEDICAL DIAGNOSTICS

2019 ◽  
pp. 42-52
Author(s):  
S.A. Novikova ◽  
E.D. Gribova ◽  
E.V. Andreev ◽  
R.V. Novichkov ◽  
P.P. Gladyshev ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Thioglycolic Acid ◽  
Medical Diagnostics ◽  
Organic Medium ◽  
Synthesis And Characterization ◽  
Exciton Peak ◽  
Additional Time ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Average Size

The present article deals with colloidal quantum dots (QDs) synthesized in an aqueous medium using thioglycolic acid (TGA), L-cysteine (L-cys) and mercaptoethylamine (MEA) as stabilizers. In contrast to high-temperature synthesis in an organic medium, this method of synthesis enables us to skip an additional time-consuming stage of hydrophilization of QDs. The resulting CdTe QDs were studied by spectroscopic methods of analysis. In the absorption spectra of the QDs there is an exciton peak. The average size of the QDs, which is about 3-4 nm, was calculated based on the position of the exciton peak, the zeta potential of the QDs was measured.

Cold and Detonation Spraying of TiB2-Cu Nanocomposites

2007 ◽  
Vol 534-536 ◽  
pp. 1373-1376 ◽  
Author(s):  
O.I. Lomovsky ◽  
Dina V. Dudina ◽  
V. Yu Ulianitsky ◽  
S.B. Zlobin ◽  
V.F. Kosarev ◽  
...  
Keyword(s):  
Particle Size ◽  
Mechanical Milling ◽  
Copper Substrate ◽  
Detonation Spraying ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Future Potential ◽  
Nanocomposite Powders ◽  
Tib2 Particles ◽  
Sprayed Coatings

TiB2-43vol.%Cu nanocomposite powders with titanium diboride particle size 50-100 nm were cold and detonation sprayed in order to fabricate coatings on a copper substrate. The powders were produced by self-propagating high-temperature synthesis (SHS) followed by mechanical milling. The temperatures during spraying were calculated and the change in the nanostructure of the powders during spraying was studied: in cold sprayed coatings the size of TiB2 particles was well retained, in detonation sprayed coatings the growth of the particles was observed, the mode of spraying greatly affecting the microstructure and the size of the particles. The hardness of cold sprayed coatings was higher compared to detonation sprayed coatings. This research shows the future potential for development of coatings with submicron and nanostructure by cold and detonation spraying of powders produced by mechanical milling.

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