Bi-combustion synthesis technique for the reduction of crystallite size of nanophosphors - a modified version

2021 ◽  
pp. 1469-1475
Author(s):  
D. S. Kshatri, Shubhra Mishra, Vikas Dubey
Keyword(s):  
Crystallite Size ◽  
Combustion Synthesis ◽  
High Efficiency ◽  
Milling Process ◽  
Synthesis Technique ◽  
Crystallite Sizes ◽  
Average Size ◽  
20 Nm ◽  
Physical And Chemical ◽  
Combustion Synthesis Technique

Nanophase materials, in recent times, have attracted many a researcher all over the world, on account of their exceptionally high efficiency in terms of morphological and optical behavior. In the nano-range order, various physical and chemical methods are employed to produce materials commercially, but the reported methods owing to their own physical conditions, limit the crystallite sizes to a certain nano-order. To prevail over this size-related limitation, a new modified bi-combustion synthesis technique (B-CST) has been introduced, which aids inthe formation of nanomaterials, with an average size of 10-20 nm, without using any ball milling process. In order to scrutinize the crystallite sizes of SrAl2O4: Eu2+, Dy3+ phosphors synthesized by CST and B-CST, the X-ray diffraction (XRD) technique is used to determine the crystalline phase only while high-resolution transmission electron microscopy (HRTEM) is used, which is the most sought-after method world-wide and is vigorously used to determine the crystallite size.

scholarly journals Combustion synthesis of nanoparticulate LiMgxMn1−xPO4 (x = 0, 0.1, 0.2) carbon composites

2010 ◽  
Vol 25 (8) ◽  
pp. 1460-1468 ◽  
Author(s):  
Marca M. Doeff ◽  
Jiajun Chen ◽  
Thomas E. Conry ◽  
Ruigang Wang ◽  
James Wilcox ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Discharge Rate ◽  
Carbon Composites ◽  
Active Materials ◽  
Coated Particles ◽  
Secondary Particles ◽  
Synthesis Technique ◽  
Carbon Coated ◽  
Mg Content ◽  
Combustion Synthesis Technique

A combustion synthesis technique was used to prepare nanoparticulate LiMgxMn1−xPO4 (x = 0, 0.1, 0.2)/carbon composites. Powders consisted of carbon-coated particles about 30 nm in diameter, which were partly agglomerated into larger secondary particles. The utilization of the active materials in lithium cells depended most strongly on the post-treatment and the Mg content and was not influenced by the amount of carbon. Best results were achieved with a hydrothermally treated LiMg0.2Mn0.8PO4/C composite, which exhibited close to 50% utilization of the theoretical capacity at a C/2 discharge rate.

Study of Nanocrystalline NiAl Alloys Prepared by Mechanical Alloying

2012 ◽  
Vol 329 ◽  
pp. 19-28 ◽  
Author(s):  
M. Gherib ◽  
A. Otmani ◽  
A. Djekoun ◽  
A. Bouasla ◽  
M. Poulain ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Crystallite Size ◽  
Milling Time ◽  
Structural Features ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size Refinement ◽  
20 Nm ◽  
Kinetics Of

Nanostructured Powders of Ni-20wt%Al and Ni-50wt%Al Were Prepared, by Mechanical Alloying under an Argon Atmosphere, from Elemental Ni and Al Powders Using a Planetary Ball Mill (type Fritsch P7) for Different Times (0.5-24h).). Microstructural and Structural Features of the Final Products Were Characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). the Results of the XRD Shows the Formation of the B2 (Ni Al) Phase after 2 Hours of Milling for both Systems. Also Detected Was the Ni3al Phase in Ni80al20after 4 Hours. Crystallite Size Refinement of the Final Product Occurred down to Nanometer Scales when the Milling Time Increased, and Attained 17 Nm in the Ni50al50System and 20 Nm in the other System, at 24 Hours. this Decrease in Crystallite Size Is Accompanied by an Increase in the Interval Level Strain. the Kinetics of Al Dissolution during the Milling Process of Ni50al50System Can Be Described by Two Regimes, Characterised by Different Values of Avrami Parameters which Are Calculated by Using the Johnson–Mehl–Avrami Formalism.

A NEW COMBUSTION SYNTHESIS TECHNIQUE FOR RARE EARTH-DOPED III-NITRIDE LUMINESCENT POWDERS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 655-658 ◽  
Author(s):  
F. E. RAMOS ◽  
R. GARCIA ◽  
G. A. HIRATA ◽  
E. J. BOSZE ◽  
J. MCKITTRICK
Keyword(s):  
Combustion Synthesis ◽  
High Purity ◽  
Exothermic Reaction ◽  
Metal Nitrate ◽  
High Chemical ◽  
Chemical Homogeneity ◽  
Synthesis Technique ◽  
Temperature Method ◽  
Rare Earth Doped ◽  
Combustion Synthesis Technique

A new low temperature method to produce ( (RE)xGa1-x)2O3(1≥x≥0 and RE=Eu, Yb, Pr and Tm) powders with high purity, high chemical homogeneity and improved crystallinity has been developed. This procedure produces finely divided powders through an exothermic reaction between the precursors. The process starts with aqueous solutions of RE(NO3)3 and Ga(NO3)3 as the precursors and hydrazine as the (non-carbonaceous) fuel. The combustion reaction occurs when heating the precursors between 150 and 200°C in a closed vessel filled with an inert gas (Ar), which yields (RExGa1-x)2O3 directly. The preparation of RE-doped Ga2O3 powders was using a new combustion synthesis technique (Hydrazine / metal nitrate method). The preparation of Eu-doped GaN was using the ammonium hexafluoro-metal method. The powders were crystalline and high-purity as determined by XPS, EDS, SEM and XRD measurements.

scholarly journals Magnetic Properties of NiZn Ferrite Nanofibers Prepared by Electrospinning

2019 ◽  
Vol 9 (20) ◽  
pp. 4297 ◽  
Author(s):  
Na ◽  
Kim ◽  
Song ◽  
Choi
Keyword(s):  
Magnetic Properties ◽  
Electromagnetic Interference ◽  
Polymer Concentration ◽  
Chemical Properties ◽  
Size Control ◽  
Precursor Solution ◽  
X Ray Diffraction ◽  
Crystallite Sizes ◽  
20 Nm ◽  
Physical And Chemical

When the size of a material is decreased to the nanoscale, the effects of forces that are not influential on a macroscopic scale become increasingly important and the electronic structure is improved. The material then exhibits significantly different physical and chemical properties than in the bulk state. The smaller the size of the material, the more exposure it receives to the nano effects, and the physical properties can be changed via size control. In this study, Ni0.5Zn0.5Fe2O4 ferrite nanofibers were prepared by electrospinning, and the sizes of the prepared samples were controlled to ensure different average diameters by controlling the polymer concentration of the precursor solution. Field emission scanning electron microscope images showed that the samples had average diameters of 224 to 265 nm. The single crystal phase of Ni0.5Zn0.5Fe2O4 and the different crystallite sizes of 13 to 20 nm were confirmed by X-ray diffraction analysis. The magnetization behavior of the samples was measured using a vibrating sample magnetometer and the result confirmed that the samples had different magnetic properties, according to the diameter and crystallite size of the nanofibers. This study suggests that control of magnetic properties and excellent electrical conductivity in a one-dimensional nanostructure can be positively applied to improve the performance of a filler for the electromagnetic-interference shielding film.

scholarly journals Combustion Synthesis of Large Bulk Nanostructured Ni65Al21Cr14Alloy

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Jiqiang Ma ◽  
Jun Yang ◽  
Qinling Bi ◽  
Licai Fu ◽  
Yonghai Kang ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Rapid Solidification ◽  
Compression Test ◽  
Fracture Strength ◽  
High Fracture ◽  
Good Ductility ◽  
Large Bulk ◽  
Density Growth ◽  
20 Nm ◽  
Combustion Synthesis Technique

A large bulk nanostructured Ni65Al21Cr14alloy with dimensions of Φ 100 mm × 6 mm was produced by combustion synthesis technique followed with rapid solidification. The Ni65Al21Cr14alloy was composed of γ′-Ni3Al/γ-Ni(Al, Cr) eutectic matrix and γ-Ni(Al, Cr) dendrite. The eutectic matrix consisted of 80–150 nm cuboidal γ′-Ni3Al and 2–5 nm γ-Ni(Al, Cr) boundary. The dentrite was comprised of high-density growth twins with about 3–20 nm in width. The nanostructured Ni65Al21Cr14alloy exhibited simultaneously high fracture strength of 2200 MPa and good ductility of 26% in compression test.

Characteristics of Porous B4C-Al2O3Composites Fabricated by the Combustion Synthesis Technique

2004 ◽  
Vol 11 (1) ◽  
pp. 5-14 ◽  
Author(s):  
H.C. Yi ◽  
J.Y. Guigné ◽  
L.A. Robinson ◽  
A.R. Manerbino ◽  
J.J. Moore
Keyword(s):  
Combustion Synthesis ◽  
Synthesis Technique ◽  
Combustion Synthesis Technique
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