scholarly journals Preparation, Characterization and Intermediate-Temperature Electrochemical Properties of Er3+-Doped Barium Cerate–Sulphate Composite Electrolyte

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2752
Author(s):  
Fufang Wu ◽  
Ruifeng Du ◽  
Tianhui Hu ◽  
Hongbin Zhai ◽  
Hongtao Wang

In this study, BaCe0.9Er0.1O3−α was synthesized by a microemulsion method. Then, a BaCe0.9Er0.1O3−α–K2SO4–BaSO4 composite electrolyte was obtained by compounding it with a K2SO4–Li2SO4 solid solution. BaCe0.9Er0.1O3−α and BaCe0.9Er0.1O3−α–K2SO4–BaSO4 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectrometry. AC impedance spectroscopy was measured in a nitrogen atmosphere at 400–700 °C. The logσ~log (pO2) curves and fuel cell performances of BaCe0.9Er0.1O3−α and BaCe0.9Er0.1O3−α–K2SO4–BaSO4 were tested at 700 °C. The maximum output power density of BaCe0.9Er0.1O3−α–K2SO4–BaSO4 was 115.9 mW·cm−2 at 700 °C, which is ten times higher than that of BaCe0.9Er0.1O3−α.

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Shrikant Saini ◽  
Ajay Kumar Baranwal ◽  
Tomohide Yabuki ◽  
Shuzi Hayase ◽  
Koji Miyazaki

Abstract The direct conversion of thermal energy into electricity is possible by thermoelectric effect. CsSnI3 perovskite has shown a way with its intrinsic ultralow thermal conductivity and large Seebeck coefficient. In this work, CsSnI3 thin films were optimized. Thin films were structurally and chemically characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). Thermoelectric properties such as electrical conductivity, Seebeck coefficient, and thermal conductivity were measured near room temperature (300 K). CsSnI3 thin films unileg thermoelectric modules were fabricated on a glass substrate. The maximum output power is obtained about 0.8 nW for five legs (25 mm × 3 mm × 600 nm) modules for the temperature difference of about 5 °C.


2009 ◽  
Vol 79-82 ◽  
pp. 353-356
Author(s):  
Wei Pan ◽  
Yan Chen ◽  
Xiao Wei He

The polyacrylonitrile(PAN)/poly (methyl methacrylate)(PMMA) blend fibers were prepared by wet-spinning technique and carbonized over the temperature range of 400-1000°C in nitrogen atmosphere. After carbonization of the blend fibers, the PMMA component removed and the PAN component left in the form of carbon nanofibers. Morphology of the carbon nanofibers were investigated via scanning electron microscopy (SEM), and the carbonization behavior of the fibers were examined via x-ray diffraction (XRD), Raman microspectrometry. The optimal condition made carbon fibers with great L/D ratio and diameter less than 200 nm. XRD and Raman spectra shows that the PAN/PMMA blend fibers treated at 600°C produced some graphite crystallite.


2014 ◽  
Vol 32 (3) ◽  
pp. 385-390
Author(s):  
Aysel Kantürk Figen ◽  
Bilge Coşkuner ◽  
Sabriye Pişkin

AbstractIn the present study, hydrogen desorption properties of magnesium hydride (MgH2) synthesized from modified waste magnesium chips (WMC) were investigated. MgH2 was synthesized by hydrogenation of modified waste magnesium at 320 °C for 90 min under a pressure of 6 × 106 Pa. The modified waste magnesium was prepared by mixing waste magnesium with tetrahydrofuran (THF) and NaCl additions, applying mechanical milling. Next, it was investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) techniques in order to characterize its structural properties. Hydrogen desorption properties were determined by differential scanning calorimetry (DSC) under nitrogen atmosphere at different heating rates (5, 10, and 15 °C/min). Doyle and Kissenger non-isothermal kinetic models were applied to calculate energy (Ea) values, which were found equal to 254.68 kJ/mol and 255.88 kJ/mol, respectively.


2019 ◽  
Vol 971 ◽  
pp. 79-84
Author(s):  
Chun Guang Zhang

As a promising third generation semiconductor material, gallium nitride (GaN) has become a research hotspot in optoelectronic field nowadays. In this paper, GaN thin films were grown by radio frequency (RF) planar magnetron sputtering of a powder GaN target in a pure nitrogen atmosphere at (0.2 – 2.0) Pa, (10 - 100) W onto various substrates such as GaAs (100), Si (100), Si (111), Al2O3(0001) and glass without any buffer layer. A clear phase transition from the metastable cubic zinc-blende (c - ZB) to the stable hexagonal wurtzite (h - WZ) dependence on substrates has been found in the GaN thin films. And the phase transition of GaN films were studied by X-ray diffraction (XRD), photoluminescence (PL) and Raman spectroscopy.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2603
Author(s):  
Andra Mihaela Onaș ◽  
Iuliana Elena Bîru ◽  
Sorina Alexandra Gârea ◽  
Horia Iovu

This study investigates the formation of a graphene oxide-polyamidoamine dendrimer complex (GO-PAMAM) and its association and interaction with bovine serum albumin (BSA). Fourier-transform infrared spectrometry and X-ray photoelectron spectrometry indicated the formation of covalent linkage between the GO surface and PAMAM with 7.22% nitrogen content in the GO-PAMAM sample, and various interactions between BSA and GO-PAMAM, including π-π* interactions at 291.5 eV for the binding energy value. Thermogravimetric analysis highlighted the increasing thermal stability throughout the modification process, from 151 to 192 °C for the 10% weight loss temperature. Raman spectrometry and X-ray diffraction analysis were used in order to examine the complexes’ assembly, showing a prominent (0 0 2) lattice in GO-PAMAM. Dynamic light scattering tests proved the formation of stable graphenic and graphenic-protein aggregates. The secondary structure rearrangement of BSA after interaction with GO-PAMAM was investigated using circular dichroism spectroscopy. We have observed a shift from 10.9% β-sheet composition in native BSA to 64.9% β-sheet composition after the interaction with GO-PAMAM. This interaction promoted the rearrangement of the protein backbone, leading to strongly twisted β-sheet secondary structure architecture.


2003 ◽  
Vol 18 (3) ◽  
pp. 236-239 ◽  
Author(s):  
L. Marosi ◽  
J. Cifré ◽  
C. Otero Areán

The new heteropoly blue compound (MoO2)0.5PMo14O42, which is relevant in the context of catalytic activity of heteropoly-molybdates, was prepared by controlled thermolysis of (NH4)3PMo12O40 at 730 K in a nitrogen atmosphere. Powder X-ray diffraction analysis showed that this compound has a cubic unit cell, space group Pn3m (No. 224), with ao=11.795(2) Å, Z=2 and DXR=4.2466 g cm−3. Computer modeling and Rietveld analysis of powder diffraction patterns led to a proposed structure of the corresponding Keggin-cage unit PMo14O42.


2006 ◽  
Vol 514-516 ◽  
pp. 18-22
Author(s):  
Shibin Zhang ◽  
Z. Hu ◽  
Leandro Raniero ◽  
X. Liao ◽  
Isabel Ferreira ◽  
...  

A series of amorphous silicon carbide films were prepared by plasma enhanced chemical vapor deposition technique on (100) silicon wafers by using methane, silane, and hydrogen as reactive resources. A very thin (around 15 Å) gold film was evaporated on the half area of the a- SiC:H films to investigate the metal induced crystallization effect. Then the a-SiC:H films were annealed at 1100 0C for 1 hour in the nitrogen atmosphere. Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to analyze the microstructure, composition and surface morphology of the films. The influences of the high temperature annealing on the microstructure of a-SiC:H film and the metal induced metallization were investigated.


2015 ◽  
Vol 1098 ◽  
pp. 69-74
Author(s):  
Eduardo R. Magdaluyo ◽  
Jomyr E. Gapasin

Yttrium doped barium cerate is considered a promising electrolyte material for solid oxide fuel cell applications due to its excellent proton conductivity. The proton conductivity characteristics of the ceramic material can be influenced by the different synthesis processing parameters. This study aimed to obtain yttrium doped barium cerate BaCe1-xYxO3-δ (x = 0.15, 0.20) using a sol-gel modified Pechini method. The phase formation and surface morphology of the yttrium doped barium cerate were investigated using x-ray diffraction and scanning electron microscopy. The thermal decomposition of the calcined ceramic material was examined using thermogravimetric analysis. Diffraction analysis confirmed the formation of perovskite crystalline structure with the presence of secondary phase yttrium doped ceria. Larger grain size with homogeneous distribution and coalescence was observed in the sintered BaCe0.80Y0.20O3-δ.


2014 ◽  
Vol 152 (3) ◽  
pp. 504-520 ◽  
Author(s):  
R. DAZA ◽  
M. A. BUSTILLO

AbstractRoot-associated stalactites (rootsicles) in Galeria da Queimada lava tube have a mineralogical composition and developmental association with microbes that render them unique. Samples were examined by X-ray diffraction, micro-Raman spectrometry and scanning electron microscopy/X-ray energy-dispersive spectroscopy. Three types of rootsicle were defined: incipient; hard (white and red); and black spongy. The incipient rootsicles still contained rotten organic material and showed the beginning of mineralization by allophane. The white hard and black spongy types were also composed of allophane, while the red hard type was composed of hydrous ferric oxi-hydroxide minerals (HFO). The allophane and HFO in the andisol covering the cave roof precipitated out of the dripwater running along the roots to form the studied rootsicles. All three types of rootsicle showed black layers, coatings, spots or patches composed of manganese oxide minerals and, occasionally, hisingerite (iron (III) phyllosilicate). An alternation of organic precipitation caused by filamentous bacteria and inorganic precipitation (the latter facilitated by pH changes in the dripwater and the cave's temperature) built up both the porous and compact rings observed in the white and red hard rootsicles. The largely straight filaments seen in the porous rings of the white hard rootsicles may be indicative of the previous presence ofLeptothrixspp., while the helical morphologies seen in the red hard rootsicles may be indicative of that ofGallionellaspp. The manganese oxide minerals detected probably formed via microbial activity. This study reflects the important role of filamentous bacteria in rootsicle formation, independent of their mineralogy.


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