Research on Properties of Ca3-x La xCo4O9 Thermoelectric Material with Adding La

2011 ◽  
Vol 287-290 ◽  
pp. 613-617 ◽  
Author(s):  
Li Peng Zhang ◽  
Xian Jin Yu ◽  
Zhi Wei Ge ◽  
Yun Hui Dong ◽  
Dang Gang Li
Keyword(s):  
Electron Microscopy ◽  
Thermoelectric Properties ◽  
Thermoelectric Material ◽  
Sol Gel ◽  
High Electrical Conductivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
High Seebeck Coefficient ◽  
Scanning Electron

Ca3Co4O9 and Ca3-xLaxCo4O9 powders were prepared by sol-gel process. The Ca-Co-O thermoelectric material ceramics were prepared. The ceramics materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The microstructure and thermoelectric properties of ceramics were researched. The results indicate that the crystal of Ca3-xLaxCo4O9 with La adding growth ideally, the material had high density and low pore rate. The Ca3-xLaxCo4O9 ceramics contain directional array plate-shaped grains with layered structure. The thermoelectric properties of Ca3-xLaxCo4O ceramics were excellent. There were high Seebeck coefficient and high electrical conductivity for Ca3-xLaxCo4O9 ceramics. The power factor increased with temperature increasing.

Research on Properties of Ca-Co-O Thermoelectric Material with Adding Sm

2011 ◽  
Vol 688 ◽  
pp. 260-265 ◽  
Author(s):  
Jie Chen Mu ◽  
Xiu Ting Wei ◽  
Li Peng Zhang
Keyword(s):  
Electron Microscopy ◽  
Thermoelectric Properties ◽  
Thermoelectric Material ◽  
Sol Gel ◽  
High Electrical Conductivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
High Seebeck Coefficient ◽  
Scanning Electron

Ca3Co4O9 and Ca3-xSmxCo4O9 powders were prepared by sol-gel process. The Ca-Co-O thermoelectric material ceramics were prepared. The ceramics materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The microstructure and thermoelectric properties of ceramics were researched. The results indicate that the crystal of Ca3-xSmxCo4O9 with Sm adding growth ideally, the material had high density and low pore rate. The Ca3-xSmxCo4O9 ceramics contain directional array plate-shaped grains with layered structure. The thermoelectric properties of Ca3-xSmxCo4O ceramics were excellent. There were high Seebeck coefficient and high electrical conductivity for Ca3-xSmxCo4O9 ceramics. The power factor increased with temperature increasing.

Preparation and Analysis of Novel Thermoelectric Material (SrxCa1-x)3Co4O9

2014 ◽  
Vol 492 ◽  
pp. 326-330
Author(s):  
Jie Wang ◽  
Li Peng Zhang ◽  
Yan Li
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Sol Gel ◽  
Ceramic Materials ◽  
High Electrical Conductivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Clear Cut ◽  
Sol Gel Process ◽  
High Seebeck Coefficient

Nanometer-sized (SrxCa1-x)3Co4O9powders were prepared using the sol-gel process. Two Ca-Co-O ceramic thermoelectric materials were then prepared and characterized with X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The microstructure and thermoelectric properties of the ceramic materials were studied. The experimental results showed that the crystals of (SrxCa1-x)3CO4grew into materials with high density and low pore rate under optimal Sr-doped conditions. The (SrxCa1-x)3Co4O9ceramic materials contain directional arrays with cube-shaped grains in a layered arrangement. The crystals were fully developed and the interface between layers was clear-cut. The thermoelectric properties of (SrxCa1-x)3Co4O9ceramics were greatly improved, with high Seebeck coefficient and high electrical conductivity. The Seebeck Coefficient positively correlated with the rise of temperature.

Preparation of Alumina Powders through Pyrocatechol, Resorcinol Mediated Sol-Gel Method

2016 ◽  
Vol 850 ◽  
pp. 742-747
Author(s):  
Xiang Zhang ◽  
Ping Yun Li ◽  
Xiao De Guo ◽  
Ting Yan
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
Xrd Study ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Scanning Electron ◽  
Organic Monomer

Ultrafine alumina powders were synthesized through pyrocatechol and resorcinol mediated sol-gel process. Aluminum nitrate was applied as the Al source and PVP was the dispersant. X-ray diffraction (XRD) study displayed that γ-Al2O3 powders formed in the range of 800-900 °C, and then γ-Al2O3 transformed to α-Al2O3 at higher temperatures, pure α-Al2O3 powders could be obtained at 1000 °C by using resorcinol as organic monomer. The results of transmission electron microscopy (TEM) revealed that Al2O3 nanoparticles with γ crystalline phase had grain sizes in the range of 5-40 nm. Scanning electron microscopy (SEM) observation displayed that the morphology of the prepared α-Al2O3 powders had aggregated bodies formed by Al2O3 grains in the range of 0.2-0.5μm. These results provide a new way of preparation of alumina powders.

SYNTHESIS AND CHARACTERIZATION OF Y2SiO5:Ce3+ PHOSPHOR MATERIALS BY SOL–GEL PROCESS

2010 ◽  
Vol 17 (01) ◽  
pp. 59-62 ◽  
Author(s):  
YOUNG-JAE KO ◽  
JONG KYU LEE ◽  
MIN-CHEOL CHU ◽  
DONG-SIK BAE
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Luminescence Spectra ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Scanning Electron

Y 2 SiO 5: Ce 3+ particles was synthesized by sol–gel process. In all samples treated at 1100°C, monoclinic X 1 phase for all cerium concentration. Luminescence spectra shows broad Ce 3+ luminescence in Y 2 SiO 5 host, which picks around 450 nm. The synthesized and calcined powders were characterized by thermogravimetry-differential scanning calorimeter (TG-DSC), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and photoluminescence spectra (PL).

Synthesis of Nano-Crystalline Magnesium Chromate Spinel by Citrate Sol-Gel Method

2011 ◽  
Vol 284-286 ◽  
pp. 730-733 ◽  
Author(s):  
Su Ping Li ◽  
Xiao Lin Jia ◽  
Ya Fang Qi
Keyword(s):  
Electron Microscopy ◽  
Crystal Size ◽  
Annealing Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Crystalline ◽  
Sol Gel Process ◽  
Initial Crystallization Temperature ◽  
Scanning Electron

Nanocrystalline MgCr2O4 with a crystal size of about 20nm is synthesized by citrate sol-gel process, which is characterized by X-ray diffraction (XRD), thermogravimetry coupled with differential thermal analysis (TG-DTA) and field emission scanning electron microscopy (FE-SEM). The initial crystallization temperature of MgCr2O4 spinel was at about 550°C, whereas that of the fully crystallized magnesium chromate spinel appeared at about 600°C. The crystal grain size increases with the annealing temperature and holding time.

Sol-Gel AL2O3 Coatings on SiC Fiber

1991 ◽  
Vol 249 ◽  
Author(s):  
Youming Xiao ◽  
Beng Jit Tan ◽  
Steven L. Suib ◽  
Francis S. Galasso
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sic Fiber ◽  
Sol Gel Process ◽  
Scanning Electron

ABSTRACTCoating of SiC (BP-SIGMA) fibers with alumina by a sol-gel process did not cause degradation even after heating to 1000°C in air for 24 h. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Auger electron spectroscopy (AES) and scanning electron microscopy (SEM ) methods were used to study the coating fiber interface.

scholarly journals Structural and optical properties of SnO2–Al2O3 nanocomposite synthesized via sol-gel route

2015 ◽  
Vol 33 (4) ◽  
pp. 714-718 ◽  
Author(s):  
Neeraj K. Mishra ◽  
Chaitnaya Kumar ◽  
Amit Kumar ◽  
Manish Kumar ◽  
Pratibha Chaudhary ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Properties ◽  
Sol Gel ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Sensing Applications ◽  
Scanning Electron

AbstractA nanocomposite of 0.5SnO2–0.5Al2O3 has been synthesized using a sol-gel route. Structural and optical properties of the nanocomposite have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray diffraction spectroscopy confirm the phase purity and the particle size of the 0.5SnO2–0.5Al2O3 nanocomposite (13 to 15 nm). The scanning electron microscopy also confirms the porosity in the sample, useful in sensing applications. The FT-IR analysis confirms the presence of physical interaction between SnO2 and Al2O3 due to the slight shifting and broadening of characteristic bands. The UV-Vis analysis confirms the semiconducting nature because of direct transition of electrons into the 0.5SnO2–0.5Al2O3 nanocomposites.

Preparation of Borosilicate Xerogel and Research on its Mineralization

2012 ◽  
Vol 476-478 ◽  
pp. 2059-2062
Author(s):  
Chen Wang ◽  
Ya Dong Li ◽  
Gu Qiao Ding
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ph Value ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Changes ◽  
Scanning Electron

Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.

scholarly journals Synthesis of Brushite from Phophogypsum Industrial Waste

2021 ◽  
Vol 12 (5) ◽  
pp. 6580-6588
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Industrial Waste ◽  
Sol Gel ◽  
Dicalcium Phosphate Dihydrate ◽  
X Ray Diffraction ◽  
Characterization Methods ◽  
X Ray ◽  
Phosphate Dihydrate ◽  
Scanning Electron

Dicalcium phosphate dihydrate (DCPD) nanoparticles, also known as brushite, are considered an important bioceramic compound. In this study, brushite was prepared from Moroccan phosphogypsum (PG) using a new sol-gel method. A two-step technique undergoes the synthesis of brushite, the preparation of anhydrite from PG followed by adding phosphoric acid in the presence of sodium hydroxide. The morphology, the chemical composition, and the crystallites size were obtained using Scanning Electron Microscopy (SEM-EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), respectively. According to the Debye-Scherrer equation, these characterization methods indicated that the synthesized brushite was highly pure according to the Ca/P ratio of 1.14 and an average crystallites size estimated at 66 nm. These results proved that the brushite was successfully synthesized from Moroccan phosphogypsum.

scholarly journals Structural and thermoelectric properties of the Pr2Zr2O7 compound

2019 ◽  
pp. 4-9
Author(s):  
Adolfo Quiroz-Rodríguez ◽  
Cesia Guarneros-Aguilar ◽  
Ricardo Agustin-Serrano
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Crystal Size ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature ◽  
Thermal Stability Of ◽  
Scanning Electron

In this research, it is presented a detailed study of the structural and thermoelectric properties of the pyrochlore zirconium Pr2Zr2O7 compound prepared by solid-state reaction (SSR) in air at ambient pressure. The synthesized sample was characterized using powder X-ray diffraction. The thermal stability of the thermoelectric compound (TE) Pr2Zr2O7 was tested by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Scanning electron microscopy shows that the crystal size varies between 0.69 and 2.81μm. Electrical conductivity (\sigma) of the sample calcined at 1400 °C presented values increase irregularly with the increasing temperature from 0.001 to 0.018 S cm-1 as expected in a semiconductor material. The thermal conductivity is lower than 0.44 - 775 W m-1 K-1 which is quite anomalous in comparison with the thermal conductivity of other oxides.

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