Synthesis and Characterization of Monodispersed Rare-earth Ion Doped CeO2 Coated on SiO2 Spheres

2008 ◽  
Vol 1074 ◽  
Author(s):  
Pandurangan Muralidharan ◽  
Seung Hwan Jo ◽  
Hyun Wook Lee ◽  
Do Kyung Kim

ABSTRACTCore–shell microspheres of monodispersed SiO2 coated with rare-earth ion doped CeO2 (Eu3+ Sm3+ Dy3+) were prepared through a sol-gel method and followed by heat treatment at 800 °C for 4 h. XRD patterns revealed the crystal structures of the doped CeO2 coated on amorphous SiO2 sphere as a shell subsequent to heat treatment at 800 °C. SEM and TEM analysis indicated the microstructures of the coating and uniform size distributions of microspheres. Photoluminescence studies showed that the luminescent property had significant influence depending on different dopant ions and the thickness of the shell coated on SiO2 spheres.

2003 ◽  
Vol 68 (8-9) ◽  
pp. 677-684 ◽  
Author(s):  
Edita Garskaite ◽  
Darizus Jasaitis ◽  
Aivaras Kareiva

A sol-gel method has been developed to prepare pure yttrium aluminum garnet Y3Al5O12 (YAG), and rare-earth substituted (Ce-Y3Al5O12, Nd-Y3Al5O12 Ho-Y3Al5O12, and Er-Y3Al5O12) samples. The XRD patterns of the polycrystalline powders sintered at 1000 ?C showed the formation of monophasic garnet materials. The micro-structural features in the polycristalline samples were studied by scanning electron microscopy. A homogeneous distribution of rare-earth do pants in the YAG lattice was achieved in all of the cases. Electrical conductivity measurements were also performed on the compacts of sol-gel derived Ln-YAG samples. In contrast to the expected dielectric behavior, the conducting properties of the examined specimens indicate metallic behavior with the resistivity increasing gradually with increasing temperature.


2012 ◽  
Vol 96 (2) ◽  
pp. 476-480 ◽  
Author(s):  
Go Kawamura ◽  
Ryota Yoshimura ◽  
Kazunari Ota ◽  
Song-Yul Oh ◽  
Norio Hakiri ◽  
...  

2007 ◽  
Vol 124-126 ◽  
pp. 1031-1034
Author(s):  
Bong Soo Jin ◽  
Bok Ki Min ◽  
Chil Hoon Doh

To find out suitable Si surface treatment and heat treatment conditions, acid treatment of Si wafer was done for lithium polysilicate electrolyte coating on Si wafer. In case of HCl treatment, the wet angle of a sample is 30o, which is the smallest wet angle of other acid in this experiment. Acid treatment time is 10 min, which is no more change of wet angle. Lithium polysilicate electrolyte was synthesized by hydrolysis and condensation of lithium silicate solution using perchloric acid. Thermal analysis of lithium polysilicate electrolyte shows the weight loss of ~23 % between 400 and 500 , which is due to the decomposition of LiClO4. The XRD patterns of the obtained lithium polysilicate electrolyte also show the decrement of LiClO4 peak at 400 . The optimum heat treatment temperature is below 400 , which is the suitable answer for lithium polysilicate electrolyte.


2021 ◽  
Vol 12 (4) ◽  
pp. 2523-2529
Author(s):  
Daniel Sam N ◽  
Anish C I ◽  
Sabeena G ◽  
Rajaduraipandian S ◽  
Manobala ◽  
...  

Sol gel methods were used for the study of the antimicrobial activity of Cd-TiO2 against gram-negative and positive bacteria. These Cd-TiO2 have been characterized by various optical and techniques. They have been exhibited by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, and infrared spectroscopy. The structures of the various XRD patterns indicate that the product has a structure. The particle size of Cd-TiO2 is 35nm. The SEM images confirm the spherical appearance of the sample. The energy X-ray spectra have been confirmed as well and then C, O, Ti, Cd, Pt element are present in Cd-TiO2. The weight percentage of Cadmium is 5.8%, Ti is 51.03%, C is 5.13% and O is 31.75% in Cd-TiO2. BET image shows that the major pore size distribution of Cd-TiO2 is ranged from 2.24 nm. The Cd-TiO2 that the antibacterial activity when tested against the pathogens only gram-negative bacteria such as Pseudomonas. The zone of minimum inhibition concentration was measured in a range of 20mm in 25μl and 30mm in 100μl.


2019 ◽  
Vol 43 (21) ◽  
pp. 8315-8324
Author(s):  
Hui Yang ◽  
Rui Wang ◽  
Yaozu Wang ◽  
Jianzhong Jiang ◽  
Xingzhong Guo

Macroporous europium-doped Ca12Al14O33 (C12A7:Eu3+) was prepared via a sol–gel method followed by heat-treatment, and the resultant macroporous C12A7:Eu3+ shows potential for practical application in metal ion detection and has a good response to Pb2+ ions.


2012 ◽  
Vol 4 (2) ◽  
pp. 65-72 ◽  
Author(s):  
Rita John ◽  
Rajaram Rajakumari

2014 ◽  
Vol 884-885 ◽  
pp. 247-250 ◽  
Author(s):  
Kai Sheng ◽  
Jie Lin Wang ◽  
Ying Li ◽  
Yi Han Wang ◽  
Meng Xue Xu ◽  
...  

Selecting lactam 2,6-pyridinedicarboxamide (PDCA) as the ligand and 1,4-butanediol as chain extender, we prepare polyurea polyurethane PDCA-PU; then, introduction of rare earth ion Eu3+ and small molecule ligands 1,10-phenanthroline (phen), synthesized binary and ternary polyurethane composite containing Eu3+, and comparing the fluorescence properties of the material. We investigated the thermal stability and luminescence properties of hybrids and found that the ternary hybrid materials exhibit better thermal stability and stronger emission intensity.


2010 ◽  
Vol 28 ◽  
pp. 211-214 ◽  
Author(s):  
Zongren LI ◽  
Peng XI ◽  
Miao ZHAO ◽  
Xiaohua GU ◽  
Qiaoyu MA ◽  
...  
Keyword(s):  
Sol Gel ◽  

2007 ◽  
Vol 121-123 ◽  
pp. 41-44 ◽  
Author(s):  
Dong Ri Zhang ◽  
Young Soo Kang

Nanoparticles of anatase TiO2 doped with 2 at.% Sc3+ and 2 at.% V5+ ions were synthesized by sol-gel method. Average crystal sizes of TiO2, TiO2+2 at.% Sc, TiO2+2 at.% V and TiO2+2 at.% (Sc+V) calculated from XRD patterns are 18.0, 16.9, 18.0, 16.2 nm, respectively. HRTEM images of TiO2 and TiO2+2 at.% (Sc+V) exhibit well-defined lattice fringe. The lattice spacings of TiO2 and TiO2+2 at.% (Sc+V) are both measured to be 3.3 Å, which correspond to the distance between the (101) planes of anatase TiO2. Raman spectra of the samples demonstrate the well dispersion of Sc3+ and V5+ ions in the TiO2 matrix. UV-vis diffuse reflectance absorption spectra of the samples show the characteristics of TiO2, and the diffuse reflectance spectra of TiO2+2 at.% V and TiO2+2 at.% (Sc+V) exhibit red shifts and weak wide absorptions in the visible region of 400-600 nm.


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