scholarly journals Synthesis and Optical Characterizations of Yb3+: CaxSr1−xF2 Transparent Ceramics

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Hongran Ling ◽  
Bingchu Mei ◽  
Weiwei Li ◽  
Yu Yang ◽  
Yongqiang Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Fluorescence Lifetime ◽  
Emission Band ◽  
Spherical Shape ◽  
Previous Literature ◽  
Precipitation Method ◽  
Transparent Ceramics ◽  
Peak Shape ◽  
Co Precipitation

In this study, 3 at.% Yb3+: CaxSr1−xF2 nanopowders were synthesized via the chemical co-precipitation method. Highly transparent 3 at.% Yb3+: CaxSr1−xF2 ceramics with various CaF2 concentrations were fabricated by hot-pressed sintering. The 3 at.% Yb3+: CaxSr1−xF2 nanopowders exhibited a spherical shape with slight agglomeration, and their particle size ranged from 26 nm to 36 nm. With an increase of the CaF2 concentration, the peak shape changed significantly and the width of the emission band increased inhomogeneously. The minimal fluorescence lifetime at the wavelength of 1011 nm of 3 at.% Yb3+: CaxSr1−xF2 transparent ceramics with various CaF2 concentrations was higher than 3.25 ms, which was longer than that of the 3 at.% Yb3+: CaF2 (2.6 ms) and the 3 at.% Yb3+: SrF2 (3.22 ms) reported in previous literature. The results indicate that incorporating Ca2+ ions into the SrF2 is an effective method to modulate the optical properties of transparent ceramics.

scholarly journals Impact of Iron on the Fe–Co–Ni Ternary Nanocomposites Structural and Magnetic Features Obtained via Chemical Precipitation Followed by Reduction Process for Various Magnetically Coupled Devices Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Reduction Process ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Magnetic Characteristics ◽  
Reduction Temperature ◽  
Fe Content ◽  
Magnetic Features ◽  
Co Precipitation

This paper presents the synthesis of Fe–Co–Ni nanocomposites by chemical precipitation, followed by a reduction process. It was found that the influence of the chemical composition and reduction temperature greatly alters the phase formation, its structures, particle size distribution, and magnetic properties of Fe–Co–Ni nanocomposites. The initial hydroxides of Fe–Co–Ni combinations were prepared by the co-precipitation method from nitrate precursors and precipitated using alkali. The reduction process was carried out by hydrogen in the temperature range of 300–500 °C under isothermal conditions. The nanocomposites had metallic and intermetallic phases with different lattice parameter values due to the increase in Fe content. In this paper, we showed that the values of the magnetic parameters of nanocomposites can be controlled in the ranges of MS = 7.6–192.5 Am2/kg, Mr = 0.4–39.7 Am2/kg, Mr/Ms = 0.02–0.32, and HcM = 4.72–60.68 kA/m by regulating the composition and reduction temperature of the Fe–Co–Ni composites. Due to the reduction process, drastic variations in the magnetic features result from the intermetallic and metallic face formation. The variation in magnetic characteristics is guided by the reduction degree, particle size growth, and crystallinity enhancement. Moreover, the reduction of the surface spins fraction of the nanocomposites under their growth induced an increase in the saturation magnetization. This is the first report where the influence of Fe content on the Fe–Co–Ni ternary system phase content and magnetic properties was evaluated. The Fe–Co–Ni ternary nanocomposites obtained by co-precipitation, followed by the hydrogen reduction led to the formation of better magnetic materials for various magnetically coupled device applications.

A homogeneous co-precipitation method to synthesize highly sinterability YAG powders for transparent ceramics

2015 ◽  
Vol 41 (2) ◽  
pp. 3283-3287 ◽  
Author(s):  
Jinsheng Li ◽  
Xudong Sun ◽  
Shaohong Liu ◽  
Xiaodong Li ◽  
Ji-Guang Li ◽  
...  
Keyword(s):  
Precipitation Method ◽  
Transparent Ceramics ◽  
Co Precipitation

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

Synthesis of mesoporous Fe-Mn bimetal oxide nanocomposite by aeration co-precipitation method: Physicochemical, structural, and optical properties

2019 ◽  
Vol 224 ◽  
pp. 65-72 ◽  
Author(s):  
Hadi Eslami ◽  
Mohammad Hassan Ehrampoush ◽  
Abbas Esmaeili ◽  
Ali Asghar Ebrahimi ◽  
Mohammad Taghi Ghaneian ◽  
...  
Keyword(s):  
Optical Properties ◽  
Precipitation Method ◽  
Structural And Optical Properties ◽  
Co Precipitation

Aluminate Green Phosphor with Small Particle Size Used for PDP via Co-Precipitation Method

2011 ◽  
Vol 295-297 ◽  
pp. 890-895
Author(s):  
Yan Dong ◽  
Yang Zhou ◽  
Xue Lin Han ◽  
Wei Jie Gu
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Small Particle ◽  
High Efficiency ◽  
Particle Growth ◽  
Solid State Reaction Method ◽  
Precipitation Method ◽  
Small Particle Size ◽  
Green Phosphor ◽  
Co Precipitation

Mg doped BaAl12O19:Mn2+ phosphor is one of the most efficient green phosphors for PDP. It is difficult to prepare the phosphor both have small particle size (< 3μm) and high luminescence. In the present work, a BaAl12O19:Mn2+ phosphor with small particle size was synthesized by the chemical co-precipitation method. Phase transformation and particle growth process during calcining process were investigated. The nucleation process was also discussed. The results show that, the phase transformation is complicated, the transition phases include BaCO3, γ-Al2O3, BaF2, BaAl2O4 and two phases contain Mn; The BaAl12O19 phase is formed from the reaction between BaAl2O4 phase and γ-Al2O3 phase, no a-Al2O3 phase appears during the entire process; The formation temperature of pure BaAl12O19 phase is 1200°C, which is lower than that in the high-temperature solid state reaction method. High efficiency BaAl12O19:Mn2+ phosphor with small particle size (< 2μm) and hexagonal flaky shape can be prepared by this method.

ChemInform Abstract: Preparation of BaMgAl10O17:Eu2+ Phosphor with Small Particle Size by Co-Precipitation Method.

ChemInform ◽  
2011 ◽  
Vol 42 (13) ◽  
pp. no-no
Author(s):  
Yan Dong ◽  
Zhisen Wu ◽  
Xuelin Han ◽  
Rong Chen ◽  
Weijie Gu
Keyword(s):  
Particle Size ◽  
Small Particle ◽  
Precipitation Method ◽  
Small Particle Size ◽  
Co Precipitation

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

High efficiency synthesis of Nd:YAG powder by a spray co-precipitation method for transparent ceramics

2018 ◽  
Vol 38 (5) ◽  
pp. 2454-2461 ◽  
Author(s):  
Wei Jing ◽  
Fang Li ◽  
Shengquan Yu ◽  
Xiangbo Ji ◽  
Tao Xu ◽  
...  
Keyword(s):  
High Efficiency ◽  
Precipitation Method ◽  
Transparent Ceramics ◽  
Co Precipitation
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