Effects of Eu Doping and Calcination Temperatures on Chemical Compositions, Microstructure and Luminescent Intensity of BaAl2O4

2018 ◽  
Vol 766 ◽  
pp. 233-240
Author(s):  
Oratai Jongprateep ◽  
Kritthin Chunwijitra
Keyword(s):  
Particle Morphology ◽  
Secondary Phase ◽  
Chemical Compositions ◽  
Luminescent Intensity ◽  
Forgery Detection ◽  
Solution Combustion ◽  
Calcination Temperatures ◽  
Secondary Phase Formation ◽  
Crack Monitoring ◽  
Combustion Technique

Photoluminescent (PL) materials are commonly utilized in applications such as leakage test, crack monitoring, banknote forgery detection, and fingerprint detection. Doping, chemical compositions and microstructure, are generally accepted as factors that influence luminescent intensity of spinel-structure phosphors such as SrAl2O4, CaAl2O4, and BaAl2O4. This study aimed at synthesizing BaAl2O4 photoluminescent powders by solution combustion technique. Effects of Eu doping and calcination temperatures on chemical compositions, microstructure and luminescent intensity of the materials were also examined. Experimental results indicated that Eu concentrations did not exhibit a significant effect on chemical composition and particle morphology. Higher calcination temperatures, on the contrary, resulted in reduction of secondary phase formation, and in alteration of morphology of particles and pores. The greatest luminescent intensity was achieved in the BaAl2O4 sample with 3 mol% Eu subjected to calcination at 900°C. Enhancement of the luminescent intensity in this sample might be attributed to minimal secondary phase and pore content.

scholarly journals Synthesis of Pr0.70Sr0.30MnO3δ and Nd0.70Sr0.30MnO3δ powders by solution-combustion technique

2011 ◽  
Vol 14 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Reinaldo Azevedo Vargas ◽  
Everton Bonturim ◽  
Rubens Chiba ◽  
Marco Andreoli ◽  
Emília Satoshi Miymaru Seo
Keyword(s):  
Solution Combustion ◽  
Combustion Technique

scholarly journals (Ti,Cr)C-Based Cermets with Varied Nicr Binder Content via Elemental SHS for Perspective Cutting Tools

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 412
Author(s):  
Stepan Vorotilo ◽  
Philipp V. Kiryukhantsev-Korneev ◽  
Boris S. Seplyarskii ◽  
Roman A. Kochetkov ◽  
Nail I. Abzalov ◽  
...  
Keyword(s):  
Solid Solution ◽  
Gas Permeability ◽  
Combustion Velocity ◽  
Cutting Tools ◽  
Secondary Phase ◽  
Fold Increase ◽  
Combustion Products ◽  
Secondary Phase Formation ◽  
Secondary Reactions ◽  
Nickel Binder

The effects of granulation of reactive mixtures Ti-Cr-C and Ti-Cr-C-Ni on the combustion temperature and velocity, as well as phase composition and mechanical properties (crushing ability) of combustion products, were studied. Granulation was associated with a 1.5-fold increase in combustion velocity, caused by a nearly 10-fold increase in gas permeability. Secondary reactions between TiC, Cr7C3, and molten Ni led to the formation of (Ti,Cr)C FCC solid solution and Ni2.88Cr1.12 intermetallics. After the combustion of Ti-Cr-C-Ni mixtures, prolonged fluorescence was registered, suggesting the exothermic nature of secondary phase formation reactions. The introduction of the nickel binder decreased the content of Cr in the solid solution (Ti,Cr)C owing to the formation of the Ni2.88Cr1.12 phase. To prevent the Cr depletion from the carbide solid solution, Ni-20%Cr binder was added to the granulated 80%(Ti + C)/20%(3Cr + 2C) mixture. Combustion of granulated mixture yielded brittle porous sinter cake, which was easy to crush and mill, whereas the combustion products from the powdered mixtures were more ductile and harder to crush.

scholarly journals Influence of ZnO addition and milling process on structure and conductivity of BaCe0.2Zr0.7Y0.1O3-δ ceramics

2021 ◽  
Vol 15 (3) ◽  
pp. 288-296
Author(s):  
Ana Ana Kaori de Oliveira Ouba ◽  
Adilson Chinelatto ◽  
Edson Grzebielucka ◽  
Kethlinn Ramos ◽  
Janaina Borcezi ◽  
...  
Keyword(s):  
Secondary Phase ◽  
Linear Shrinkage ◽  
High Energy ◽  
Milling Process ◽  
Sintering Aids ◽  
X Ray Diffraction ◽  
Sintering Aid ◽  
Secondary Phase Formation ◽  
Precursor Powders ◽  
Perovskite Lattice

Precursor powders for BaCe0.2Zr0.7Y0.1O3-?(BCZY27) ceramics were synthesized by a modified Pechinimethod and calcined at 900?C for 12 h. The calcined BCZY27 powders were milled in eccentric and in high energy mill with the addition of 2 and 4mol% ZnO as sintering aid. The effects of milling and sintering aids on the sinterability and electrical conductivity were studied. The linear shrinkage in thermomechanical analyses started at 1050?C for the BCZY27 with 4mol% ZnO processed in eccentric mill. Theoretical density above of 90%TD was obtained for the BCZY27 milled with 4mol% ZnO and sintered at 1400?C for 4h. X-ray diffraction analysis of the BCZY27 ceramics sintered at 1400?C confirmed the presence of BaCe0.2Zr0.7Y0.1O3-? and Y0.4Ce0.6O1.8 phases. The incorporation of Zn into perovskite lattice leads to the secondary phase formation. SEM and EDS analyses confirmed the presence of Y0.4Ce0.6O1.8 phase. The sintering was assisted by BaO-ZnO eutectic, which was reflected by the increase of activation energy values for grain boundary conduction. The milling processing did not affect the conductivity properties. The obtained BCZY27 dense sample has conductivity of 7.60 ? 10?3 S/cm at 500?C.

Secondary phase formation by liquid immiscibility in Ca3Ta(Ga1−xAlx)3Si2O14 melt

2019 ◽  
Vol 522 ◽  
pp. 117-124
Author(s):  
Yuki Honda ◽  
Hiromasa Niinomi ◽  
Jun Nozawa ◽  
Junpei Okada ◽  
Satoshi Uda
Keyword(s):  
Phase Formation ◽  
Secondary Phase ◽  
Liquid Immiscibility ◽  
Secondary Phase Formation

Magnetic study of GdxBi1-xFeO3 multiferroics synthesized by solution combustion technique

2018 ◽  
Author(s):  
Arminder Kaur ◽  
Shivani Negi ◽  
Somnath ◽  
Arun Kumar ◽  
S. K. Sharma ◽  
...  
Keyword(s):  
Magnetic Study ◽  
Solution Combustion ◽  
Combustion Technique

scholarly journals First Hydrogenation Enhancement in TiFe Alloys for Hydrogen Storage Doped with Yttrium

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 242 ◽  
Author(s):  
Catherine Gosselin ◽  
Jacques Huot
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Storage ◽  
Secondary Phase ◽  
Chemical Compositions ◽  
Hydrogen Capacity ◽  
The Matrix

The aim of this investigation was to improve the first hydrogenation of TiFe by adding yttrium. The compositions studied were TiFe + x wt.% Y with x = 4, 6, and 8. From electron microscopy it was found that all alloys were multiphase with a matrix of TiFe phase containing less than 0.4 at.% of Y and a secondary phase rich in yttrium. When x increased, the chemical compositions of the matrix changed and the secondary phase changed. The sample with 8% of yttrium had the fastest kinetics. The hydrogen capacity increased with the amount of Y.

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