scholarly journals Photoluminescence and EPR spectrum of ZnO:Mn nanocrystals

2018 ◽  
Vol 26 (1) ◽  
pp. 69-72 ◽  
Author(s):  
O. V. Kovalenko ◽  
M. F. Bulaniy ◽  
V. Y. Vorovskiy ◽  
O. V. Khmelenko
Keyword(s):  
Heat Treatment ◽  
Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis ◽  
Epr Spectra ◽  
Short Term ◽  
Epr Spectrum ◽  
Shell Surface ◽  
Admixture Concentration ◽  
Ultrasonic Spray ◽  
Nonequilibrium Conditions

Nanocrystals of ZnO:Mn were obtained by ultrasonic spray pyrolysis and had dimensions of d ~ 36 nm. The changes of photoluminescence end EPR spectra of these nanocrystals in dependence of Mn admixture concentration ( 2–8 at. %) and also at heat treatment in air during 1 hour at T = 850 ̊C were investigated. It is shown that under short-term (7–10 s) nonequilibrium conditions of ZnO:Mn nanocrystals forming, they consist of a nuclens and shell surface, in which, predominantly, the Mn admixture is concentrated. After annealing, the Mn admixture diffuses into the nucleus of a nanocrystal.

Fabrication and Characterization of Various Calcium Phosphate Powders by Ultrasonic Spray Pyrolysis Technique

2006 ◽  
Vol 317-318 ◽  
pp. 57-60
Author(s):  
H.J. Wang ◽  
Young Keun Jeong ◽  
Kyung Sik Oh ◽  
B.H. Kim ◽  
Seong Hee Lee ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Calcium Phosphate ◽  
Spray Pyrolysis ◽  
Single Phase ◽  
Spray Pyrolysis Technique ◽  
Calcium Phosphates ◽  
Ultrasonic Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis Technique ◽  
Starting Solution ◽  
Ultrasonic Spray

To overcome the difficulty of preparing the stoichiometric single phase calcium phosphate materials, ultrasonic spray pyrolysis was used to fabricate various calcium phosphates. Effect of the initial Ca/P ratios and pyrolysis temperature were investigated in preparation of single phase materials. Also thermal stability of the obtained powders was estimated with the heat treatment in the air. Crystallinity of the powders was analyzed using XRD and FT-IR. The HAp and β-TCP powders with single phase could be obtained from their stoichiometric Ca/P ratios of 1.50 and 1.67, respectively. These single phase powders with good crystallinity and stoichiometry were stable with respect to heat treatment up to 1000oC. The particle size of these powders would be controlled by the concentration of starting solution.

Fireworks: How to Simulate the Manufacture and Operation in the Atmosphere with the Substitution of Ultrasonic Spray Pyrolysis

2018 ◽  
Vol 15 (2) ◽  
pp. 147-156
Author(s):  
Rebeka Rudolf ◽  
Urban Ferčec ◽  
Mohammed Shariq
Keyword(s):  
Spray Pyrolysis ◽  
Final Section ◽  
Web Of Science ◽  
Raw Materials ◽  
Ultrasonic Spray Pyrolysis ◽  
Physiochemical Properties ◽  
Physical Size ◽  
Respiratory Problems ◽  
Ultrasonic Spray ◽  
Temperature Ranges

Background: This review provides a closer look at recent work in the field of fireworks manufacture, which could see the replacement of micron-sized particles with their nano-scaled counterparts. Moreover, we also discuss micron-sized particles as well as nanoparticles (NPs) from K, Fe, Al, Ti, Ba, etc., that are produced in the atmosphere as a result of these fireworks. One of the possible technological substitutes for fireworks is presented in detail, i.e., the use of ultrasonic spray pyrolysis (USP) technology. Method: We searched Google, Web of Science and PubMed for a literature survey of fireworks and their products: firecrackers, micron-sized and nanoparticles. Moreover, we used some of our own knowledge and experimental data to strengthen the possibility of simulating the synthesis of firework products on the laboratory scale. Results: The use of nano reactants and oxidisers has seen a substantial increase in the sound efficiency and a decrease in the amount of chemicals used, making fireworks more eco-friendly. The application of Al- and Ti-based nano flash powder in the size range from 35 nm to 50 μm resulted in a significant improvement in the ignition properties of the fireworks. Under changing aerodynamic conditions, it is difficult to collect them as samples for real-time monitoring, needed for their characterization or the testing of their harmfulness under laboratory conditions. As a result, NPs below 100 nm in the surroundings could be easily inhaled into the lungs and cause more pulmonary and respiratory problems than micron-sized particles. USP produces nanoparticles in the laboratory that could replace the conventional micron-sized firecracker raw materials, or nanoparticles that are similar to those formed by fireworks. It will also help to identify the physiochemical properties of the airborne particulates in order to understand and evaluate their impact. </P><P> This review could be valuable for a controlled economic synthesis through USP, and in the use of nanopowders in pyrotechnology that could reduce pollution to a great extent, thus contributing to the growth and good practise of the fireworks industry. With respect to the USP synthesis, we have also discussed in detail the physical (size, shape) and chemical (composition) characteristics of Al2O3 and TiO2 NPs from different precursors and their temperature ranges. An in-depth explanation for a comparative analysis for the formation mechanism of nanoparticles through both fireworks and USP is presented in the final section. We can produce nanoparticles in the laboratory with ultrasonic spray pyrolysis that have similar properties to those produced from fireworks and can then be used for further testing.

Ultrasonic spray pyrolysis deposited CTS thin film: Variation of thiourea concentration in the film

2021 ◽  
Author(s):  
Sabina Rahaman ◽  
M. Anantha Sunil ◽  
Monoj Kumar Singha ◽  
Kaustab Ghosh
Keyword(s):  
Thin Film ◽  
Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis ◽  
Ultrasonic Spray ◽  
Thiourea Concentration

scholarly journals Strong texture tuning along different crystalline directions in glass-supported CeO2 thin films by ultrasonic spray pyrolysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Inti Zumeta-Dubé ◽  
José Manuel García Rangel ◽  
Jorge Roque ◽  
Issis Claudette Romero-Ibarra ◽  
Mario Fidel García Sánchez
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Morphological Characteristics ◽  
Ultrasonic Spray Pyrolysis ◽  
Cost Effective ◽  
Growth Direction ◽  
Large Area ◽  
Smart Windows ◽  
Ultrasonic Spray

AbstractThe strong facet-dependent performance of glass-supported CeO2 thin films in different applications (catalysis, smart windows, etc.) has been the target of diverse fundamental and technological approaches. However, the design of accurate, cost-effective and scalable methods with the potential for large-area coverage that produce highly textured glass-supported CeO2 thin films remains a technological challenge. In the present work, it is demonstrated that under proper tuning conditions, the ultrasonic spray pyrolysis technique enables one to obtain glass-supported polycrystalline CeO2 films with noticeable texture along both the (100) and (111) directions, as well as with randomly oriented crystallites (no texture). The influence of flow rates, solution molarity, and substrate temperature on the texture and morphological characteristics, as well as optical absorption and Raman response of the deposited films, is evaluated. The obtained results are discussed on the basis of the combined dependence of the CeO2-exposed surfaces on the thermodynamic stability of the corresponding facets and the reaction kinetics, which modulate the crystallite growth direction.

One-pot synthesis of hematite-alumina hollow sphere composite by ultrasonic spray pyrolysis technique with high adsorption capacity toward PAHs

2021 ◽  
Vol 32 (4) ◽  
pp. 1060-1069
Author(s):  
Hossein Vojoudi ◽  
Jahan B. Ghasemi ◽  
Ahmadreza Hajihosseinloo ◽  
Bahareh Bastan ◽  
Alireza Badiei
Keyword(s):  
Spray Pyrolysis ◽  
Adsorption Capacity ◽  
Hollow Sphere ◽  
Spray Pyrolysis Technique ◽  
Ultrasonic Spray Pyrolysis ◽  
High Adsorption ◽  
One Pot ◽  
Ultrasonic Spray Pyrolysis Technique ◽  
Ultrasonic Spray ◽  
High Adsorption Capacity

Transparent MIS capacitors on plastic substrates fabricated by high-frequency ultrasonic spray pyrolysis

2021 ◽  
Vol 44 (2) ◽  
Author(s):  
Ovier Obregon ◽  
José A Luna-Lopez ◽  
Pedro Rosales ◽  
Mario Moreno ◽  
Abdu Orduña-Diaz ◽  
...  
Keyword(s):  
Spray Pyrolysis ◽  
High Frequency ◽  
Ultrasonic Spray Pyrolysis ◽  
Plastic Substrates ◽  
Ultrasonic Spray ◽  
Mis Capacitors
Sign in / Sign up

Export Citation Format

Share Document