In this work,we report that the thermoelectric properties of Bi（0.52）Sb（1.48）Te3alloy can be enhanced by being composited with Mn Te nano particles（NPs）through a combined ball milling and spark plasma sintering...In this work,we report that the thermoelectric properties of Bi（0.52）Sb（1.48）Te3alloy can be enhanced by being composited with Mn Te nano particles（NPs）through a combined ball milling and spark plasma sintering（SPS）process.The addition of Mn Te into the host can synergistically reduce the lattice thermal conductivity by increasing the interface phononscattering between Bi（0.52）Sb（1.48）Te3 and MnTe NPs,and enhance the electrical transport properties by optimizing the hole concentration through partial Mn^2＋ acceptor doping on the Bi^3＋ sites of the host lattice.It is observed that the lattice thermal conductivity decreases with increasing the percentage of Mn Te and milling time in a temperature range from 300 Kto 500 K,which is consistent with the increasing of interfaces.Meanwhile,the bipolar effect is constrained to high temperatures,which results in the figure of merit z T peak shifting toward higher temperature and broadening the z T curves.The engineering z T is obtained to be 20%higher than that of the pristine sample for the 2-mol%Mn Te-added composite at a temperature gradient of 200 K when the cold end temperature is set to be 300 K.This result indicates that the thermoelectric performance of Bi0.52Sb1.48Te3 can be considerably enhanced by being composited with Mn Te NPs.展开更多
Our aim was to investigate the effects of MnTE-2-PyP on some markers of inflammation and lipid peroxidation in mouse asthma model. 24 female mice were divided into four groups: group 1, controls;group 2, injected with...Our aim was to investigate the effects of MnTE-2-PyP on some markers of inflammation and lipid peroxidation in mouse asthma model. 24 female mice were divided into four groups: group 1, controls;group 2, injected with ovalbumin (OVA);group 3, treated with MnTE-2-PyP;and group 4, treated with ovalbumin and MnTE-2-PyP. The mice from groups 2 and 4 were injected with 10 μg OVA and 1 mg Imject Alum? in 100 μL phosphate buffered saline (PBS) on days 0 and 14. The animals from groups 1 and 3 were injected with 100 μL PBS + Imject Alum? (1:1). The animals from groups 2 and 4 were subjected to a 30 min aerosol challenge of 1% ovalbumin on days 24, 25 and 26 and those from groups 1 and 3 were subjected to aerosol challenge of PBS at the same time and duration. One hour before inhalation, and 12 hours later the animals from groups 3 and 4 were injected with 100 μL MnTE-2-PyP solution in PBS containing 5 mg/kg. The total cell number, total protein content and 8-isoprostane, IL-4 and IL-5 levels in the bronchialveolar lavage fluid increased in group 2 as compared to the control group. Malone dialdehyde content in the lung homogenate and IgE levels in the serum also increased in this group. The total cell number, total protein content, and levels of 8-isoprostane, IL-4, IL-5 and IgE decreased significantly in group 4 as compared to the OVA group. The parameters set out above in group 3 did not differ significantly from those of the control group. MnTE-2-PyP administered intraperitoneally, 48 hours after the last nebulization, reduced the inflammation and lipid peroxidation in mouse asthma model.展开更多
Electron-electron interactions(EEIs),quantum interference,and the effects of disorder on transport properties are essential topics in condensed matter physics.A series of our characterization work demonstrates that th...Electron-electron interactions(EEIs),quantum interference,and the effects of disorder on transport properties are essential topics in condensed matter physics.A series of our characterization work demonstrates that the morphology of Bi_(2)Te_(3)/MnTe bilayer film mainly depends on the magnetic substrate's growth mode and thickness.We propose that the temperature-dependent quantum interference of the electron wave function caused by disorder drives the transition from weak antilocalization(WAL) to weak localization(WL).Due to spin regulation,WL under low fields originates from the ferromagnetism in MnTe.The quantum interference effect(QIE) model analysis gives the degree of impurity scattering of the electron wave function.The electron wave is scattered by impurities,which causes the Berry phase to change from π to 0,producing a complete WL behavior.The stacked structure provides tunable degrees of freedom,allowing for independent optimization of topological properties and magnetic order through preferential growth orientation of topological insulator(TI) and magnetic layers,respectively.展开更多
With years of development, SnTe as a homologue of PbTe has shown great potentialfor thermoelectric applications in p-type conduction, and the most successfulstrategy is typified by alloying for maximizing the valence ...With years of development, SnTe as a homologue of PbTe has shown great potentialfor thermoelectric applications in p-type conduction, and the most successfulstrategy is typified by alloying for maximizing the valence band degeneracy.Among the known alloy agents, MnTe has been found to be one of the most effectiveenabling a band convergence for an enhancement in electronic performance ofSnTe, yet its solubility of only ~15 at% unfortunately prevents a full optimizationin the valence band structure. This work reveals that additional PbTe alloying notonly promotes the MnTe solubility to locate the optimal valence band structure butalso increases the overall substitutional defects in the material for a substantialreduction in lattice thermal conductivity. In addition, PbTe alloying simultaneouslyoptimizes the carrier concentration due to the cation size effect. These features allenabled by such a solute manipulation synergistically lead to a very high thermoelectricfigure of merit, zT of ~1.5 in SnTe with a 20 at% MnTe and a 30 at% PbTealloying (Sn0.5Mn0.2Pb0.3Te), demonstrating the effectiveness of solute manipulationfor advancing SnTe and similar thermoelectrics.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1601213 and 51472052)the Funds from Institute of Physics,Chinese Academy of Sciences
文摘In this work,we report that the thermoelectric properties of Bi（0.52）Sb（1.48）Te3alloy can be enhanced by being composited with Mn Te nano particles（NPs）through a combined ball milling and spark plasma sintering（SPS）process.The addition of Mn Te into the host can synergistically reduce the lattice thermal conductivity by increasing the interface phononscattering between Bi（0.52）Sb（1.48）Te3 and MnTe NPs,and enhance the electrical transport properties by optimizing the hole concentration through partial Mn^2＋ acceptor doping on the Bi^3＋ sites of the host lattice.It is observed that the lattice thermal conductivity decreases with increasing the percentage of Mn Te and milling time in a temperature range from 300 Kto 500 K,which is consistent with the increasing of interfaces.Meanwhile,the bipolar effect is constrained to high temperatures,which results in the figure of merit z T peak shifting toward higher temperature and broadening the z T curves.The engineering z T is obtained to be 20%higher than that of the pristine sample for the 2-mol%Mn Te-added composite at a temperature gradient of 200 K when the cold end temperature is set to be 300 K.This result indicates that the thermoelectric performance of Bi0.52Sb1.48Te3 can be considerably enhanced by being composited with Mn Te NPs.
文摘Our aim was to investigate the effects of MnTE-2-PyP on some markers of inflammation and lipid peroxidation in mouse asthma model. 24 female mice were divided into four groups: group 1, controls;group 2, injected with ovalbumin (OVA);group 3, treated with MnTE-2-PyP;and group 4, treated with ovalbumin and MnTE-2-PyP. The mice from groups 2 and 4 were injected with 10 μg OVA and 1 mg Imject Alum? in 100 μL phosphate buffered saline (PBS) on days 0 and 14. The animals from groups 1 and 3 were injected with 100 μL PBS + Imject Alum? (1:1). The animals from groups 2 and 4 were subjected to a 30 min aerosol challenge of 1% ovalbumin on days 24, 25 and 26 and those from groups 1 and 3 were subjected to aerosol challenge of PBS at the same time and duration. One hour before inhalation, and 12 hours later the animals from groups 3 and 4 were injected with 100 μL MnTE-2-PyP solution in PBS containing 5 mg/kg. The total cell number, total protein content and 8-isoprostane, IL-4 and IL-5 levels in the bronchialveolar lavage fluid increased in group 2 as compared to the control group. Malone dialdehyde content in the lung homogenate and IgE levels in the serum also increased in this group. The total cell number, total protein content, and levels of 8-isoprostane, IL-4, IL-5 and IgE decreased significantly in group 4 as compared to the OVA group. The parameters set out above in group 3 did not differ significantly from those of the control group. MnTE-2-PyP administered intraperitoneally, 48 hours after the last nebulization, reduced the inflammation and lipid peroxidation in mouse asthma model.
基金financially supported by the National Natural Science Foundation of China (Nos.52371204, 52201233,and 52031014)
文摘Electron-electron interactions(EEIs),quantum interference,and the effects of disorder on transport properties are essential topics in condensed matter physics.A series of our characterization work demonstrates that the morphology of Bi_(2)Te_(3)/MnTe bilayer film mainly depends on the magnetic substrate's growth mode and thickness.We propose that the temperature-dependent quantum interference of the electron wave function caused by disorder drives the transition from weak antilocalization(WAL) to weak localization(WL).Due to spin regulation,WL under low fields originates from the ferromagnetism in MnTe.The quantum interference effect(QIE) model analysis gives the degree of impurity scattering of the electron wave function.The electron wave is scattered by impurities,which causes the Berry phase to change from π to 0,producing a complete WL behavior.The stacked structure provides tunable degrees of freedom,allowing for independent optimization of topological properties and magnetic order through preferential growth orientation of topological insulator(TI) and magnetic layers,respectively.
基金This work is supported by the National Key Research and Development Program of China(2018YFB0703600)the National Natural Science Foundation of China(51861145305[the BRICS project]and 51772215)+3 种基金Fundamental Research Funds for Science and Technology Innovation Plan of Shanghai(18JC1414600)the Fok Ying Tung Education Foundation(20170072210001)“Shu Guang”Project Supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation,Shanghai Natural Science Foundation(19ZR1459900)the Fundamental Research Funds for the Central Universities.A.B.acknowledges support by Russian Foundation for Basic Research under grant 18-52-80005(BRICS).
文摘With years of development, SnTe as a homologue of PbTe has shown great potentialfor thermoelectric applications in p-type conduction, and the most successfulstrategy is typified by alloying for maximizing the valence band degeneracy.Among the known alloy agents, MnTe has been found to be one of the most effectiveenabling a band convergence for an enhancement in electronic performance ofSnTe, yet its solubility of only ~15 at% unfortunately prevents a full optimizationin the valence band structure. This work reveals that additional PbTe alloying notonly promotes the MnTe solubility to locate the optimal valence band structure butalso increases the overall substitutional defects in the material for a substantialreduction in lattice thermal conductivity. In addition, PbTe alloying simultaneouslyoptimizes the carrier concentration due to the cation size effect. These features allenabled by such a solute manipulation synergistically lead to a very high thermoelectricfigure of merit, zT of ~1.5 in SnTe with a 20 at% MnTe and a 30 at% PbTealloying (Sn0.5Mn0.2Pb0.3Te), demonstrating the effectiveness of solute manipulationfor advancing SnTe and similar thermoelectrics.
