Stabilization of cubic phase in scandium‐doped zirconia nanocrystals synthesized with sol‐gel method

2018 ◽  
Vol 102 (6) ◽  
pp. 3236-3243 ◽  
Author(s):  
Alexander Sobolev ◽  
Albina Musin ◽  
Gene Whyman ◽  
Konstantin Borodianskiy ◽  
Olga Krichevski ◽  
...  
Keyword(s):  
Sol Gel ◽  
Cubic Phase ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals Nanomaterial Host Bands Effect on the Photoluminescence Properties of Ce-Doped YAG Nanophosphor Synthesized by Sol-Gel Method

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
L. Guerbous ◽  
A. Boukerika
Keyword(s):  
Energy Levels ◽  
Sol Gel ◽  
Yellow Emission ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Annealing Temperatures

Cerium trivalent (Ce3+) doped YAG nano-sized phosphors have been successfully synthesized by sol-gel method using different annealing temperatures. The samples have been characterized by X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC) analysis, Fourier transform infrared (FTIR) spectroscopy, and steady photoluminescence (PL) spectroscopy. X-ray diffraction analysis indicates that the pure cubic phase YAG was formed and strongly depends on the cerium content and the annealing temperature. It was found that the grain size ranges from 30 to 58 nm depending on the calcination temperature. The YAG: Ce nanophosphors showed intense, green-yellow emission, corresponding to Ce3+5d1→2F5/2,2F7/2transitions and its photoluminescence excitation spectrum contains the two Ce3+4f1→5d1, 5d2bands. The crystal filed splitting energy levels positions 5d1and 5d2and the emission transitions blue shift with annealing temperatures have been discussed. It was found that the Ce3+4f1ground state position relative to valence band maximum of YAG host nanomaterial decreases with increasing the temperature.

Very Low-Temperature, Gram-Scale Synthesis of Monodisperse BaTiO3 Nanocrystals via an Interfacial Hydrolysis Reaction

2008 ◽  
Vol 1094 ◽  
Author(s):  
Daniel E. Morse ◽  
Richard L. Brutchey
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Cubic Phase ◽  
Vapor Diffusion ◽  
Gel Method ◽  
Sol Gel Method ◽  
Stabilizing Agents ◽  
Nanocrystal Growth ◽  
Ptcr Effect ◽  
Post Synthesis

AbstractA vapor diffusion sol-gel method is reviewed for the preparation of high-quality BaTiO3 nanocrystals on the gram scale at very low temperatures. The synthesis is based on the kinetically controlled introduction of water into a solution of the bimetallic alkoxide, BaTi(O2C4H9)6, where slow hydrolysis then occurs at the vapor-solution interface followed by nucleation and nanocrystal growth at 16 °C. The resulting 6-nm, quasi-spherical nanocrystals are both monodisperse (without stabilizing agents or size selecting purification) and highly crystalline (without any post-synthesis heat treatment), and are isolated in yields near 100%. Based on new permittivity and calorimetry data, the crystal structure of the nanocrystals is most likely in the paraelectric cubic phase (space group Pm3m) at room temperature, which corroborates previous diffraction data. It was also demonstrated that the BaTiO3 nanocrystals can be doped with trivalent lanthanum cations using the same low-temperature vapor diffusion sol-gel method to yield donor-doped Ba1−xLaxTiO3, which exhibits a considerable PTCR effect.

scholarly journals Preparation of Compensation Ions Codoped SrTiO3:Pr3+ Red Phosphor with the Sol-Gel Method and Study of Its Luminescence Enhancement Mechanism

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Dan Guo ◽  
Xiaodong Zhang ◽  
Jiangni Yun
Keyword(s):  
Electric Field ◽  
Sol Gel ◽  
Spectral Characteristics ◽  
Charge Compensation ◽  
Cubic Phase ◽  
Red Phosphor ◽  
Luminescence Enhancement ◽  
Gel Method ◽  
Sol Gel Method ◽  
Enhancement Mechanism

SrTiO3:Pr3+ is the most representative titanate matrix red phosphor for field emission display (FED). The red luminous efficiency of SrTiO3:Pr3+ will be greatly improved after the compensation ions codoping, so SrTiO3:Pr3+ red phosphor has been a research focus at home and abroad. SrTiO3:Pr3+, SrTiO3:Pr3+, Mg2+, and SrTiO3:Pr3+, Al3+ phosphors are synthesized by a new sol-gel method. Crystal structure, spectral characteristics, and luminescence enhancement mechanism of the sample were studied by XRD and PL spectra. The results showed that after co-doped, SrTiO3:Pr3+ phosphor is single SrTiO3 cubic phase, the main emission front is located at 614 nm, corresponding to Pr3+ ions 1D2→3H4 transition emission. SrTiO3:Pr3+, Mg2+ and SrTiO3:Pr3+, Al3+ phosphor luminescence intensity is enhanced, but the main luminescence mechanism is not changed. Acceptor impurity x = Mg2+, Al3+ will replace Ti bit after being doped into the crystal lattice to form XTi- charge compensation corresponding defect centers PrSr+ to reduce the demand of Sr2+ or Ti3+ vacancy. While Sr-doped Pr will make lattice distortion and transition energy of 4f-5d is very sensitive to crystal electric field changes around Pr atom. Doping different impurities will make electric field distribution around the icon have a different change. It increases energy transfer of 4f-5d transition and improves the luminous intensity of SrTiO3:Pr3+ red phosphor.

scholarly journals Characterization of Calcia Stabilized Zirconia as a solid Electrolyte Made through a sol gel Method in Solid Oxide Fuel Cell

2019 ◽  
Vol 9 (1) ◽  
pp. 3056-3060
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Electrolyte ◽  
Sol Gel ◽  
Solid Oxide ◽  
Cubic Phase ◽  
Oxide Fuel ◽  
Stabilized Zirconia ◽  
Gel Method ◽  
Sol Gel Method

Solid Oxide Fuel Cell (SOFC) is a solid-state energy conversion device which produces electricity through the conversion of chemical energy directly to electrical energy. The research was carried out to characterize Calcia Stabilized Zirconia (CSZ) that was made using sol gel method. In this study, the production of CSZ pellets consisted of three steps. First step was the extraction of ZOC (ZrOCl28H2O) and second step was the production of Zr(OH)4 and the last step was dissolution of ZrOH4 into HCl and then adding CaO to get CSZ powder. The CSZ powder was then pressed to form pellets, followed by sintering at 1200 oC for 3 hours. The characterization was conducted using X ray diffraction to analyze the presence of impurities as well as the formation of cubic phase and scanning electron microscope was used to observe the pores in the microstructure. From the XRD data and SEM analysis, it can be concluded that the Calcia Stabilized Zirconia as a solid electrolyte in SOFC using sol gel method gave promising results.

A COMPOSITE ELECTROLYTE FOR AN SOFC CONSISTING OF A CERIA SHEET AND A ZIRCONIA FILM DEPOSITED BY THE SOL-GEL METHOD

1997 ◽  
Vol 496 ◽  
Author(s):  
Reiichi Chiba ◽  
Fumikatsu Yoshimura ◽  
Junichi Yamaki
Keyword(s):  
Sol Gel ◽  
Open Circuit ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Composite Electrolyte ◽  
Gel Method ◽  
Sol Gel Method ◽  
Zirconia Film ◽  
Gel Film ◽  
A Cell

ABSTRACTWe investigated a composite electrolyte for solid oxide fuel cells prepared by coating a ceria sheet (Ce0.8Gd0.2O2-d or GDC ) with a scandia alumina doped zirconia (0.850ZrO2-0.110Sc2O3-0.04Al2O3) film by the sol-gel method. The sol-gel film annealed at 1200°C was examined by X-ray diffraction analysis and found to be in a cubic phase at room temperature. The ionic conductivity of this film is comparable to that of bulk sintered at 1620°C. Scanning electron microscope observations revealed that the film forms a good interface with the electrolyte of the ceria sheet, even though the annealing temperature is as low as 1200°C.We fabricated a single cell consisting of a composite electrolyte, a La0.8Sr0.2MnO3 cathode and a Ni-YSZ anode. The composite electrolyte consisted of zirconia film about one micron thick deposited by the sol-gel method and a 0.2 mm thick ceria sheet.A cell operated with moist H2 and O2 gas exhibited an open circuit voltage of 1.00 V at 800°C. This value is much closer to the value of 1.13 V expected from the Nernst equation than the value of 0.76 V for a cell with a ceria sheet but without the sol-gel film.

Synthesis and Photocatalytic Property of N-doped BiVO$lt;inf$gt;4$lt;/inf$gt; via Sol-Gel Method Using Corn Stem as Template

2014 ◽  
Vol 29 (8) ◽  
pp. 807
Author(s):  
WANG Min ◽  
NIU Chao ◽  
DONG Zhan-Jun ◽  
CHE Yin-Sheng ◽  
DONG Duo ◽  
...  
Keyword(s):  
Sol Gel ◽  
Photocatalytic Property ◽  
Gel Method ◽  
Sol Gel Method

Fe2O3 - TiO2 THIN FILMS PREPARED BY SOL-GEL METHOD

2011 ◽  
Vol 10 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Ramona-Crina Suciu ◽  
Marcela Corina Rosu ◽  
Teofil Danut Silipas ◽  
Emil Indrea ◽  
Violeta Popescu ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Tio2 Thin Films ◽  
Gel Method ◽  
Sol Gel Method

NiO-doped CaCu3Ti4O12 Thin Film by Sol-Gel Method

2013 ◽  
Author(s):  
Dong XU ◽  
Qi SONG ◽  
Ke ZHANG ◽  
Hong-Xing XU ◽  
Yong-Tao YANG ◽  
...  
Keyword(s):  
Thin Film ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method
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