In this paper, a series of Sb-doped and Bi-doped Cu_(2)Sn_(1-x)M_(x)Se_(3) samples(M = Sb, Bi) are prepared by vacuum melting combined with the spark plasma sintering process. The effects of different atomic doping am...
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In this paper, a series of Sb-doped and Bi-doped Cu_(2)Sn_(1-x)M_(x)Se_(3) samples(M = Sb, Bi) are prepared by vacuum melting combined with the spark plasma sintering process. The effects of different atomic doping amounts on their properties are discussed. Structural studies indicate that all obtained samples comprise a single Cu_(2)SnSe_(3) phase. Sb and Bi atoms are experimentally demonstrated to be efficient cation dopants for increasing the transport performance. Compared with that doping on the cation site,Bi doping is much more efficient in increasing the electron concentration of the Cu_(2)SnSe_(3) system. Ultimately, a high figure of merit of 0.36 is achieved in the Cu_(2)Sn_(0.94)Sb_(0.06) Se_(3) sample at 773 K due to the enhanced power factor and lowered lattice thermal conductivity,which are 1.73 times higher than those of the pure *** results provide an efficient approach to enhance thermoelectric performance via other doping atoms, which could also be applied to copper-based chalcogenide materials.
A kind of p-type segmented Bi2 Te3/CoSB3 thermoetectric material was preparea oy sparse ptasma sintering（ SPS ） . When the segmented materials were used at the temperature ranging from 300 K to 800 K, the junction t...
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A kind of p-type segmented Bi2 Te3/CoSB3 thermoetectric material was preparea oy sparse ptasma sintering（ SPS ） . When the segmented materials were used at the temperature ranging from 300 K to 800 K, the junction temperature was optimized, which is about 500 K, and the corresponding length ratio of CoSb3 to Bi2 Te3 is about 15 ： 2. The measured maximum power output of segmented materials is abont 320 W·m^-2, which is about 1.8 times as high as that of monolithic material CoSb3 under the same measuring conditions.
Porous alumina of regular spherical particles was fabricated with the spark plasma sintering （SPS） and then compared to those obtained through conventional hot pressing （HP）. The effects of the parameters of the h...
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Porous alumina of regular spherical particles was fabricated with the spark plasma sintering （SPS） and then compared to those obtained through conventional hot pressing （HP）. The effects of the parameters of the heating process on porosity were also investigated, Microstructural studies suggest that porous ingots including regular pores be made out of regular spherical alumina particles due to the close sphere packages. A comparative study on the relative necks of the specimens produced by SPS and HP indicates an enhancement of neck growth with SPS. Contrasting the theoretical values to the experimental results over the relative necks indicates that a proper relationship between the relative necks and the porosity can be established by a sintering model.
The PAn-PEO-PAn triblock copolymer with the PEG chain length of 400 was synthesized by chemical oxidation copolymerization of aniline and α,ω-bis（p-aminophenyl）poly（ethylene glycol）and characterized by FT-IR and...
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The PAn-PEO-PAn triblock copolymer with the PEG chain length of 400 was synthesized by chemical oxidation copolymerization of aniline and α,ω-bis（p-aminophenyl）poly（ethylene glycol）and characterized by FT-IR and *** experimental results show that the copolymer particles are of μtypical core-shell structure after the self-assembly process in *** conductivity is much lower than that of the pure *** suspension containing 20 vol% PAn-PEO-PAn tiblock copolymer in silicone oil exhibits.a typical electrorheological （ER） effect in DC electric *** it shows a lower leakage current density than that of the pure PAn-based ER ***,the PEO shell hinders the electric hop among PANI chains and decreases the current density of ER fluids in an external electric *** the same time the interface polarity improves the ER effects.
The microwave magnetic properties of the ball milled FeCo panicles were investigated as functions of ball milling time （ t ） using microwave electromagnetic parameters analysis techniques. The results show that the ...
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The microwave magnetic properties of the ball milled FeCo panicles were investigated as functions of ball milling time （ t ） using microwave electromagnetic parameters analysis techniques. The results show that the imaginary part of intrinsic dynamic permeability （ ui ） of the ball- milled panicles is much bigger than that of raw powders. ui strongly depends on t and exhibits several slightly damped ferromagnetic resonances. These phenomena are in qualitative agreement with the formation of the corresponding microstructure or the Aharoni ＇ s model of non-uniform exchange resonance modes. The present microwave permeabilhy behavior indicates that nanocrystalline materials with the same grain size may exhibit different properties that depend upon the microstructure, which provides a possibility for manufacturing high performance microwave absorber.
Planar micro-supercapacitors show great potential as the energy storage unit in miniaturized electronic devices. Asymmetric structures have been widely inves- tigated in micro-supercapacitors, and carbon-based materia...
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Planar micro-supercapacitors show great potential as the energy storage unit in miniaturized electronic devices. Asymmetric structures have been widely inves- tigated in micro-supercapacitors, and carbon-based materials are commonly applied in the electrodes. To integrate different metal oxides in both electrodes in micro-supercapacitors, the critical challenge is the pairing of different faradic metal oxides. Herein, we propose a strategy of matching the voltage and capadtance of two faradic materials that are fully integrated into one high-performance asymmetric micro-supercapacitor by a facile and controllable fabrication process. The fabricated micro-supercapacitors employ MnO2 as the positive active material and Fe203 as the negative active material, respectively. The planar asymmetric micro-supercapacitors possess a high capacitance of 60 F-cm-3, a high energy density of 12 ***-3, and a broad operation voltage range up to 1.2 V.
The spark plasma sintering （SPS） was applied to prepare α-Si3 N4 ceramics of different densities with magnesia, silicon dioxide, alumina as the sintering aids. The mechanism of liquid phase sintering （LPS） wus d...
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The spark plasma sintering （SPS） was applied to prepare α-Si3 N4 ceramics of different densities with magnesia, silicon dioxide, alumina as the sintering aids. The mechanism of liquid phase sintering （LPS） wus discussed and the factors influencing the density of the prepared samples were analyzed. The dielectric constant of sintered samples was tested. The experimental results show that the density can be controlled from 2.48 g/ cm^3 to 3.09 g/ cm^3 while the content of the sintering aids and the sintering temperature alter and the dielectric constant is closely dependent on the density of obtained samples.
TiAl/Ti2AlC composites were prepared by in-situ hot pressing of TilAl/C powders mixtures and sintered at different temperatures were investigated by X- ray diffraction （ XRD ） of samples. The reaction procedure of T...
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TiAl/Ti2AlC composites were prepared by in-situ hot pressing of TilAl/C powders mixtures and sintered at different temperatures were investigated by X- ray diffraction （ XRD ） of samples. The reaction procedure of Ti-Al-C system could be divided into three stnges. Below 900℃ , Ti reacts with Al to form TiAl intermetallics ; above 900 ℃ , C reacts with remain Ti to form TiC triggered by the exothermal reaction of Ti and Al ; TiAl reacts with TiC to produce dense TiAl/Ti2AlC *** the holding stage, ternary Ti2AlC develops to layered polycrystal and composites pyknosis in the meanwhile. The mechanism of synthesis and microstructure was especially discussed.
The temperature field during the whole process of SPS sintering TiB2 -BN sample was numerically simulated based on the simplification of the temperature rising process. The result shows that the highest temperature is...
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The temperature field during the whole process of SPS sintering TiB2 -BN sample was numerically simulated based on the simplification of the temperature rising process. The result shows that the highest temperature is found in the punch and the heat flows from punch to sample and die in SPS sintering system. In the radial direction, the center temperature of the sample is much higher than the circumference temperature of the sampie. In the axial direction, the center temperature of the sample is lower than the border temperature of the sampie. The temperature difference in the sample is growing bigger in the sintering process and reaches the maximum at the end of the heating-up process.
We studied a method to prepare a novel titanium dioxide(TiO_(2))composite photocatalyst,starting from improving the separation efficiency of photogenerated electrons and *** TiO_(2)microspheres were prepared by sol-ge...
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We studied a method to prepare a novel titanium dioxide(TiO_(2))composite photocatalyst,starting from improving the separation efficiency of photogenerated electrons and *** TiO_(2)microspheres were prepared by sol-gel method and loaded onto Ti3C2Tx(Mxene).The high electrical conductivity of Mxene was utilized to transfer photogenerated electrons quickly and effectively prevent their *** adjusting the addition amount of Mxene,the hydrogen production efficiency of the sample was greatly improved,and the maximum efficiency reached 135.2μmol·g^(-1)·h^(-1),which was twice that of pure TiO_(2).The nanocomposites were characterized by XRD,PL,TEM and SEM analysis and electrochemical methods,and the test proved that the improvement of hydrogen production efficiency was caused by the improvement of the separation efficiency of photogenerated electrons and *** work demonstrates the application of Mxene as a catalyst to improve efficiency and broadens the application prospects of Mxene.
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