1wt% multiwalled carbon nanotube （MWNTs） reinforced alumina composites was sintered to full density by spark plasma sintering. And pure alumina and graphite/alumina composites were also prepared by the same way for ...
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1wt% multiwalled carbon nanotube （MWNTs） reinforced alumina composites was sintered to full density by spark plasma sintering. And pure alumina and graphite/alumina composites were also prepared by the same way for comparison. Indentation and single edge V-notched beam （SEVNB） toughness were measured respectively. The experimental results show that MWNTs could not improve toughness of alumina too much as that once expected. And SEVNB toughness was more valid than indentation toughness.
MgO thin films were deposited on Si（100） substrates by laser ablation under various substrate temperatures （Tsub）,expecting to provide a candidate buffer layer for the textured growth of functional perovskite oxid...
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MgO thin films were deposited on Si（100） substrates by laser ablation under various substrate temperatures （Tsub）,expecting to provide a candidate buffer layer for the textured growth of functional perovskite oxide films on Si *** effect of Tsub on the preferred orientation,crystallinity and surface morphology of the films was *** films in single-phase were obtained at 473-973 *** increasing Tsub,the preferred orientation of the films changed from （200） to （111）.The crystallinity and surface morphology was different too,depending on *** Tsub=673 K,the MgO film became uniform and smooth,exhibiting high crystallinity and a dense texture.
Serial material model （Dilute model）and Limited Units （LU）method were employed to analyze the performance of binary piezo-composite *** reckoned electric potential deployments illustrated difference while the part...
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Serial material model （Dilute model）and Limited Units （LU）method were employed to analyze the performance of binary piezo-composite *** reckoned electric potential deployments illustrated difference while the particles were *** piezoelectricities were also calculated according to the model,and furthermore comparation suggested that small particles living in the tolerance improve the piezoelectricity of *** coinciding with analyses were processed simultaneously. Ceramics were milled for different time in order to control the concentration of particle *** results showed that the filled particles enhanced the piezoelectricity of binary piezo-composite system efficiently whereas too many chips deteriorated the performance of piezo-composites.
Electrical conductivity and seebeck coefficient at different temperatures,and thermal conductivity at room temperature for various doped polyaniline (PAn) samples were measured,and the thermoelectric figure of merit Z...
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Electrical conductivity and seebeck coefficient at different temperatures,and thermal conductivity at room temperature for various doped polyaniline (PAn) samples were measured,and the thermoelectric figure of merit ZT was *** effects of preparation methods and temperature on thermoelectric properties were *** results show that the electrical conductivity and the seebeck coefficient of PAn are strongly dependent on the preparation conditions and *** electrical conductivity becomes larger and the seebeck coefficient becomes smaller as PAn molecular weight *** by organic acid and HCl results in an increase in both electrical conductivity and Seebeck coefficient of PAn,and therefore ZT *** electrical conductivity increases and the seebeck coefficient decreases as the temperature increases when TT *** thermal conductivity is lower,and insensitive to the sample preparation conditions.
Raw Mg,Si powder were used to fabricate Mg2Si bulk thermoelectric generator by spark plasma sintering （SPS）.The optimum parameters to synthesize pure Mg2Si powder were found to be 823 K,0 MPa,10 min with excessive c...
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Raw Mg,Si powder were used to fabricate Mg2Si bulk thermoelectric generator by spark plasma sintering （SPS）.The optimum parameters to synthesize pure Mg2Si powder were found to be 823 K,0 MPa,10 min with excessive content of 10wt% Mg from the stoichiometric ***2Si bulk was synthesized and densified simultaneously at low temperature （823 K） and high pressure （higher than 100 MPa） from the raw powder,but Mg,Si could not react completely,and the sample was not very dense with some microcracks on the ***,Mg,Si powder reacted at 823 K,0 MPa,10 min in SPS chamber to form Mg2Si green compact,again sintered by SPS at 1023 K,20 MPa,5 *** fabricated sample only contained Mg2Si phase with fully relative density.
Iridium thin films have been deposited on Si3N4（100 nm）/Si（100） substrates by magnetron sputtering. And then iridium film micro-patterns were fabricated by ion milling technique. The atomic force microscopy （AFM...
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Iridium thin films have been deposited on Si3N4（100 nm）/Si（100） substrates by magnetron sputtering. And then iridium film micro-patterns were fabricated by ion milling technique. The atomic force microscopy （AFM） measurements reveal that there is a very fiat and smooth surface with an average roughness of 0.64 nm for the iridium films. The X-ray diffraction also reveals that the deposited iridium films have a polycrystalline microstructure with （111） plane preferential orientation. The electrical resistivity of the iridium films was also measured and discussed.
Skutterudite CoAs3 is a potentially important thermoelectric material. Morse potential is employed here to carry out molecular dynamics simulations of nanobulk CoAs3 at the temperature of 0 K. The stress-strain relati...
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Skutterudite CoAs3 is a potentially important thermoelectric material. Morse potential is employed here to carry out molecular dynamics simulations of nanobulk CoAs3 at the temperature of 0 K. The stress-strain relationships under uniaxial tensile and/or compressive strain are obtained. The elastic modulus, extreme strength and deformation mechanism are studied. The simulation results indicate that nanobulk CoAs3 abruptly ruptures at much higher strain level under tension than conventional bulk CoAs3. Both the extreme stresses under tension and compression are much higher than those of conventional bulk CoAs3.
Fe doped In2O3 samples （In1-xFex）2O3 （x=0, 0.05, 0.1, 0.2 and 0.3） on glass substrate were prepared by sol-gel method. The XRD results demonstrate that the solubility of Fe ions in In2O3 matrix is around 20%, abov...
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Fe doped In2O3 samples （In1-xFex）2O3 （x=0, 0.05, 0.1, 0.2 and 0.3） on glass substrate were prepared by sol-gel method. The XRD results demonstrate that the solubility of Fe ions in In2O3 matrix is around 20%, above which impurity phase can be observed. The transmittance of the samples with x=0, 0.05, 0.1 and 0.2 are above 80% in the visible region while the transimittance of the glass is 90%. The transmittance curves slightly red-shifts as x increasing. All of the samples except x=0 are ferromagnetic at room temperature. The highest saturation magnetization moment is reached in the sample x=0.2 with 330 emu/cm3, and the coercive force is 169 Oe which is also the largest in our samples. The results indicate that the addition of Fe ions could tune the structure, the ferromagnetism and optical property in the In2O3 matrix.
Fe-Ni-Al mixtures as hot-pressing sintering additive to Titanium diboride （TiB2） were studied. It is found that liquid alloy formed under high temperature hardly has effects on the densification behaviors of TiB2-in...
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Fe-Ni-Al mixtures as hot-pressing sintering additive to Titanium diboride （TiB2） were studied. It is found that liquid alloy formed under high temperature hardly has effects on the densification behaviors of TiB2-independent. Fe-Ni-Al additive just works as filler between TiB2 particles and does not change the TiB2-independent sintering behaviors. Pressing mode has a great effect on the liquid flowing between TiB2 particles. Multiple-steps pressing mode will give more time and space for the liquid flowing and improve the relative density of TiB2-Fe-Ni-Al cermet.
Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state r...
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Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state reaction. The bulk materials with 30 nm and 5 μm were prepared by spark plasma sintering of the nanosized and microsized Mg2Si powder, respectively. Both the samples show n-type conduction and the Seebeck coefficient of the sintered samples increase determinately with the grain size decrease from 5 μm to 30 nm. On the other hand, the electrical and thermal conductivity decrease with the decrease of grain size. Accordingly, decreasing their grain size increases their thermoelectric-figure-of-merit. A maximum thermoelectric figure of merit of 0.36 has been obtained for the nanostuctured Mg2Si sample at 823 K, which is 38% higher than that of microsized Mg2Si bulk materials and higher than results of other literatures. It could be expected that the properties of the nanocomposites could be further improved by doping optimization.
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