Preparation of BaMgAl10O17:Eu2+ phosphor with small particle size by co-precipitation method

2011 ◽  
Vol 509 (8) ◽  
pp. 3638-3643 ◽  
Author(s):  
Yan Dong ◽  
Zhisen Wu ◽  
Xuelin Han ◽  
Rong Chen ◽  
Weijie Gu
2011 ◽  
Vol 295-297 ◽  
pp. 890-895
Author(s):  
Yan Dong ◽  
Yang Zhou ◽  
Xue Lin Han ◽  
Wei Jie Gu

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 ◽  
2011 ◽  
Vol 42 (13) ◽  
pp. no-no
Author(s):  
Yan Dong ◽  
Zhisen Wu ◽  
Xuelin Han ◽  
Rong Chen ◽  
Weijie Gu

2021 ◽  
Author(s):  
Tianyu Hu ◽  
Zhiquan Yu ◽  
Shan Liu ◽  
Bingyu Liu ◽  
Zhichao Sun ◽  
...  

Citric acid (CA) modified Ni3P catalysts with small particle size were prepared by H2 temperature-programmed reduction (H2-TPR) of the precursors, which were prepared by co-precipitation with Ni(NO3)2·6H2O and (NH4)2HPO4, using...


Author(s):  
Dr. Jambla Neha ◽  
Saroch Vikas ◽  
Johar Smita

Rasashastra deals with the Rasa Aushadhis, the drugs of metallic and mineral origin. Mercury is used in most of the Rasaaushadhis. The toxicity of Mineral and metallic preparations are reduced to such an extent by various procedures of Shodhana, Marana etc. that Mercury converts its inherent property of toxicity into medicinal property. Rasa Aushadhis works quickly on the body because due to their small particle size, their absorption starts from the oral mucosa itself. The action of drugs depends largely upon the Anupana i.e. the vehicle for the drug. Rasacharayas have mentioned various Rasa preparations like Bhasmas, Parpati, Pottali, Manduras, Karpooras etc. along with their doses, dose schedule and Anupana / Sahapana etc. The principles of Rasaaushadhis when correlated in modern era are found to be scientifically accurate. We may say that Rasacharyas had already mastered the science of nanotechnology, purification, action of metabolic catalysts, biotransformation and preservation of medicines. The Ayurvedic drugs can be harmful for our body when not administered in proper dosage as per mentioned in classic literatures.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  

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.


RSC Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1952-1959
Author(s):  
Yi Zhao ◽  
Fangfang Peng ◽  
Yangchuan Ke

Emulsion with small particle size and good stability stabilized by emulsifiers was successfully prepared for EOR application.


Sign in / Sign up

Export Citation Format

Share Document