scholarly journals Promising solid electrolyte material for an IT-SOFC: crystal structure of the cerium gadolinium holmium oxide Ce0.8Gd0.1Ho0.1O1.9 between 295 and 1023 K

2018 ◽  
Vol 74 (2) ◽  
pp. 236-239 ◽  
Author(s):  
Sri Rahayu ◽  
Jennifer S. Forrester ◽  
Girish M. Kale ◽  
Mojtaba Ghadiri
Keyword(s):  
Crystal Structure ◽  
Solid Oxide Fuel Cells ◽  
Solid Electrolyte ◽  
Sol Gel ◽  
Fluorite Structure ◽  
Sodium Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature ◽  
Co Doped

The crystal structure of Ce0.8Gd0.1Ho0.1O1.9 (cerium gadolinium holmium oxide) has been determined from powder X-ray diffraction data. This is a promising material for application as a solid electrolyte for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Nanoparticles were prepared using a novel sodium alginate sol-gel method, where the sodium ion was exchanged with ions of interest and, after washing, the gel was calcined at 723 K in air. The crystallographic features of Gd and Ho co-doped cerium oxide were investigated around the desired operating temperatures of IT-SOFCs, i.e. 573 ≤ T ≤ 1023 K. We find that the crystal structure is a stable fluorite structure with the space group Fm\overline{3}m in the entire temperature range. In addition, the trend in lattice parameters shows that there is a monotonic increase with increasing temperature.

scholarly journals Structural Characteristics of Bimetallic Catalysts Supported on Nano-Ceria

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
J. F. Bozeman ◽  
H. Huang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Structural Characteristics ◽  
Low Cost ◽  
Sol Gel ◽  
Average Particle Size ◽  
Fluorite Structure ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Ceria

Cu-Pt bimetal catalysts supported on nanocrystalline CeO2(nano-ceria) are synthesized via the low-cost sol-gel approach followed by impregnation processing. The average particle size of the catalytic composites is 63 nm. Ceria nanopowders sequentially impregnated in copper solution and then in Pt solution transformed into Pt-skin-structured Cu-Pt/ceria nanocomposite, based on the surface elemental and bulk compositional analyses. The ceria supporter has a fluorite structure, but the structure of Cu and Pt catalytic contents, not detected by X-ray diffraction spectroscopy due to the low loading level, is yet conclusive. The bimetallic catalytic nanocomposites may potentially serve as sulfur-tolerant anode in solid oxide fuel cells.

Structural and Optical Properties of Al Co-Doped ZnCoO Thin Film

2014 ◽  
Vol 989-994 ◽  
pp. 656-659
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Al Doping ◽  
X Ray ◽  
Uv Emission ◽  
Uv Absorption Spectroscopy ◽  
Co Doped

Al co-doped ZnCoO thin film has been prepared by a sol-gel method. The structural and optical properties of the sample were investigated. X-ray diffraction and UV absorption spectroscopy analyses indicate that Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.

Structure and Up-Conversion Luminescence Properties of Er3+-Yb3+Co-Doped TiO2 Nanocrystals Prepared by Sol-Gel Method

2009 ◽  
Vol 66 ◽  
pp. 167-170 ◽  
Author(s):  
Zhen Zhong Zhang ◽  
Ji Hong Zhang ◽  
Wei Zhou ◽  
Ming Xia Song ◽  
Wei Li ◽  
...  
Keyword(s):  
Titanium Tetrachloride ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Red Emission ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Co Doped

Er3+/Yb3+ co-doped TiO2 nanocrystals were prepared by Sol-gel method in which titanium tetrachloride was adopted as the precursor. The structure, particle size, and optical properties of samples were characterized by X-ray diffraction(XRD), Field emission-Scanning Electron Microscopy(FE-SEM) and photoluminescence(PL) spectra. Er3+ concentration was fixed at 1.0mol%, and Yb3+ concentration was changed from 3 to 10mol%. Intense upconversion luminescence was observed when the samples were excited by 980nm laser. The dependence of upconversion luminescence on Yb3+ concentration was presented. The results show that the upconversion luminescence increases with the Yb3+ concentration and gets its peak at 5%. The ratio of red emission to green emission(R/G) was strikingly enhanced with the increase of Yb3+ concentration. Under the excitation of 980nm, the green emission in the range of 520-570nm (2H11/2, 4S3/2→4I15/2) and the red emission in the range of 640~690nm (4F9/2 →4I15/2) are both due to two photons process. The possible upconversion mechanism was discussed.

scholarly journals ENHANCED FERROELECTRICITY AND FERROMAGNETISM OF (Y, Ni) CO-DOPED BiFeO3 MATERIALS

2018 ◽  
Vol 56 (1A) ◽  
pp. 219
Author(s):  
Dao Viet Thang
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Saturation Polarization ◽  
Perovskite Type ◽  
Co Doped

In this study, multiferroicMultiferroic Bi1-xYxFe0.975Ni0.025O3 (x = 0.00, 0.05, 0.10, and 0.15) called as (Y, Ni)                co-doped BiFeO3 materials were synthesized by a sol-gel method.  and characterized by X-ray diffraction diagrams and(XRD), energy-dispersive X-ray (EDX) and vibrating sample magnetization (VSM) measurements demonstrated. The result showed that Bi1-xYxFe0.975Ni0.025O3all investigated materials waspresent a single phase of the perovskite-type rhombohedral structure. Ferromagnetism and ferroelectricity of the Bi1-xYxFe0.975Ni0.025O3 materials have been investigated. Results showed that the co-doping by (Y, Ni) for (Bi, Fe)  have affected in enhancing by the (Y, Ni) co-doping, as a result the ferroelectric polarization and magnetization of BiFeO3. The magnetic characterization indicated that the ferromagnetic behavior wasthe initial BiFeO3 materialwere enhanced with increasing concentration of Y3+ for (Y, Ni) co-substituted of BiFeO3. Which could beion. It is attributed to the defferentdifference of the magnetic momentmoments of Ni2+ and Fe3+, and+ ions, as well as the Y3+-Fe3+,+ and Y3+-Ni2+ super-exchange interaction. Theinteractions. The characteristics of the investigated materials, such as remanent magnetization (Mr), saturation magnetization (Ms), remanent polarization (2Pr) and saturation polarization (2Ps) continuously increase upon increasing in the range of x from 0.00 to 0.15. When x = 0.15, the values of Mr and Ms are 0.078 and 0.794 emu/g, respectively. The values of 2Pr and 2Ps are 16.58 and 27.99 µC/cm2, respectively. Origin of ferromagnetic and ferroelectric properties of Bi1-xYxFe0.975Ni0.025O3 materials will be discussed in this paper.

scholarly journals The Synthesis and Characterizations of CeY0.15Er0.05O2 Nanocrystal

2021 ◽  
Vol 22 (2) ◽  
pp. 341-344
Author(s):  
Handan Özlü Torun
Keyword(s):  
Crystal Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Impedance Analysis ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Species ◽  
Unit Cell Size ◽  
Structure Properties

CeY0.15Er0.05O2 nanocrystal powders prepared via sol-gel method. Phases identification have been made X-ray diffraction, SEM-EDX, FTIR, thermal and impedance analysis. XRD data show that all powders were obtained with cubic fluorite structure. With the increase of sintering temperature, the unit cell size decreased and the crystal size increased. The particle size was found to be in the range of 150 to 270 nm. It was found that the nitrates and organic species seen in the FTIR results. It was observed that organic species disappeared at sintering temperatures selected according to thermal analysis results. Impedance measurements of the pelletized sample were made. Although the crystal structure properties were good, it was found that the conductivity values were low.

PL Properties of (Ba, Ca)2( Si, P)O4: Eu Synthesized by Various Annealing and Cooling Process

2021 ◽  
Vol 1016 ◽  
pp. 231-235
Author(s):  
Shota Ando ◽  
Hiromi Nakano ◽  
Koichiro Fukuda
Keyword(s):  
Crystal Structure ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Slow Cooling ◽  
X Ray ◽  
Host Materials ◽  
Emission Color ◽  
Increasing Temperature ◽  
X Ray Absorption ◽  
Color Emission

We have been investigating the series of P doped Ca2SiO4 (C2S) using Eu2+ or Eu3+ as activator with various colors. The crystal structure of C2S is particularly easily controlled by heating because the established polymorphs of C2S are, in the order of increasing temperature, γ, β, α’L, α’H, and α. In order to control the crystal structure, the phosphors were synthesized and then annealed at temperatures 1473 K-1773 K. The crystal structures and PL properties were compared between slow cooling and quenching (cooled in water). We found unique phenomena when the phosphors were treated by quenching process. In the case of (Ba1-xCax)2(Si0.94P0.06)O4:Eu3+ ( 0.25 ≤ x ≤ 1), color emission changed from red to blue-white for the phosphor with a high concentration of Ba and quenched at 1773 K. In general, Eu3+ doped phosphors showed the red emission color in any host materials. However, Ba-included and quenched-treatment phosphors emitted a bright white color. The mechanism and relationship between the PL property and crystal structure were characterized carefully using X-ray diffraction, electron microscope and X-ray absorption fine structure.

Effects of Annealing on Properties of (Na,Mg):ZnO Thin Films Deposited by Sol-Gel Method

2014 ◽  
Vol 898 ◽  
pp. 33-36 ◽  
Author(s):  
Cai Zhen Zhang ◽  
Yong Gang Chen ◽  
Su Liu
Keyword(s):  
Annealing Temperature ◽  
Sol Gel ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Coating Method ◽  
Method Effects ◽  
Structural Surface ◽  
Co Doped

Na/Mg co-doped (Na,Mg):ZnO films were fabricated on pyrex glass substrates by sol-gel spin-coating method. Effects of annealing on properties of the films were particularly investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance spectra. The internal stress of the films annealed at different temperature was calculated. Experimental and analytical results show that some NaCl freeze-out derivatives will appear on films when the annealing temperature is too low, with the increasing annealing temperature, the c-axis tensile stress is sharply decreased first, then the c-axis stress was changed into press stress and its value is increased continuously, so the structural, surface and the optical properties of the films improve first and deteriorate afterwards.

Preparation and properties of solid electrolyte CaxBi1.7−xW0.3O3.45−0.5x electrolyte material by sol–gel combution method

2019 ◽  
Vol 12 (05) ◽  
pp. 1951001
Author(s):  
Jie Yang ◽  
Changan Tian ◽  
Yu Wang ◽  
Junjie Meng ◽  
Dongdong Ji ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Combustion Method ◽  
Solid Oxide ◽  
Electrochemical Studies ◽  
Oxide Fuel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Differential Thermogravimetric Analysis

CaxBi[Formula: see text]W[Formula: see text]O[Formula: see text] (CBW) ([Formula: see text], 0.05, 0.10, 0.15, 0.20, 0.30) electrolyte material were synthesized by sol–gel self-combustion method. The samples were characterized by thermogravimetric-differential thermogravimetric analysis(TG-DSC), X-ray diffraction, scanning electron microscopy (SEM), porosity and electrochemical impedance spectroscopy (EIS). The results show the powders CaxBi[Formula: see text]W[Formula: see text]O[Formula: see text] (CBW) with fluorite crystal structure can be obtained after the precursor was calcined at 760∘C. When sintered at 780∘C for 2[Formula: see text]h, the compact ceramic sintered with relative density higher than 97% can be obtained. The electrochemical studies showed that CaxBi[Formula: see text]W[Formula: see text]O[Formula: see text] (CBW) have high ionic conductivity after 780∘C sintering. The sample Ca[Formula: see text]Bi[Formula: see text]W[Formula: see text]O[Formula: see text] exhibits a conductivity of 0.07978 S[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] at 750∘C, and the activation energy is 0.845[Formula: see text]eV, which is expected to be applied to the electrolyte materials for intermediate temperature solid oxide fuel cells (SOFC).

Insight into the Structural, Electrical, and Magnetic Properties of Al-Substituted BiFeO3 Synthesised by the Sol–Gel Method

2020 ◽  
Vol 75 (3) ◽  
pp. 249-256
Author(s):  
Mukhtar Ahmad ◽  
Rizwan Ali ◽  
Atiq ur Rehman ◽  
Akbar Ali ◽  
Ishrat Sultana ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Sol Gel ◽  
Random Access ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Auto Combustion ◽  
Ferroelectric Random Access Memories

AbstractMultiferroics with chemical formula BiAlxFe1−xO3 (x = 0, 0.1, 0.2, and 0.3) and substituted by Al are synthesised using sol–gel auto-combustion. The materials are sintered at 500 °C for 5 h. In the ongoing study, the crystal structure of BiAlxFe1−xO3 was investigated by X-ray diffraction. After confirming the rhombohedral single-phase crystal structure, various characterisation techniques, such as scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping images, electrical properties, Fourier transform infrared spectroscopy, and vibrating sample magnetometry (VSM), were used to investigate the synthesised samples. The grain size estimated from SEM images decreased as Al contents increased. Elemental composition was confirmed by EDX spectra. Direct current electrical resistivity increased whereas drift mobility decreased with increasing Al contents. The VSM results of Al-doped BiFeO3 (BFO) demonstrate that BFO crystals with size >60 nm show anti-ferromagnetic behaviour, which is evident in the present study. The increase in Al doping results in an increase in coercivity, as grain size and coercivity are inversely related with each other. This is because of the replacement of Fe3+ by Al3+ ions, which weakens the sub-lattice interactions. It has been observed that BFO materials with such parameters are favourable for ferroelectric random access memories where data can be written electrically and read magnetically.

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