The Experts below are selected from a list of 7842 Experts worldwide ranked by ideXlab platform
Xiaoyuan Zhou - One of the best experts on this subject based on the ideXlab platform.
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synergistic effect of bismuth and indium codoping for high thermoelectric performance of Melt Spinning snte alloys
ACS Applied Materials & Interfaces, 2019Co-Authors: Huan Tan, Bin Zhang, Guoyu Wang, Xingchen Shen, Lijie Guo, Guiwen Wang, Xiao Zhang, Xiaoyuan ZhouAbstract:In this work, a nonequilibrium Melt Spinning (MS) technology combined with hot pressing was adopted for rapid synthesizing of SnTe compounds in less than 1 h. The refined microstructure generated by MS significantly decreases the lattice thermal conductivity. Compared to the pristine SnTe sample prepared by traditional Melting and long-term annealing, the Melt-spun one reveals a 15% lower thermal conductivity of ∼6.8 W/m K at room temperature and a 10% higher zT of ∼0.65 at 900 K. To further improve the electrical transport properties of the SnTe system, elements of Bi and In are introduced. It was found that Bi and In codoping can enhance Seebeck coefficients in a broad temperature range via optimizing carrier density and introducing resonant states. Point defects and nanoparticles introduced by Bi and In codoping remarkably enhanced phonon scattering and decreased lattice thermal conductivities. Finally, a significant enhancement on the thermoelectric performance was achieved: a peak zT of 1.26 at 900 K and an average zT of ∼0.48 over the temperature range of 300-900 K are obtained in Sn0.9675Bi0.03In0.0025Te. This work demonstrates that MS combined with appropriate doping could be an effective strategy to improve the thermoelectric performance of SnTe-related samples.
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rapid preparation of ge0 9sb0 1te1 x via unique Melt Spinning hierarchical microstructure and improved thermoelectric performance
Journal of Alloys and Compounds, 2019Co-Authors: Huan Tan, Bin Zhang, Guoyu Wang, Yongjin Chen, Xingchen Shen, Lijie Guo, Xiaodong Han, Xiaoyuan ZhouAbstract:Abstract Thermoelectric semiconductors based on GeTe has been proved to be an important materials for converting waste heat into electricity. In this study, we demonstrate an enhancement of thermoelectric performance for p-type Ge0.9Sb0.1Te1+x by a unique Melt Spinning method combined with hot pressing (MS-HP), through which increased Seebeck coefficients and reduced thermal conductivities are achieved simultaneously. Moreover, the MS technique greatly gives rise to a variety of microstructures, such as the fine Ge precipitates, twins and nano-domains, all of which contribute to the significantly reduced thermal conductivities. Finally, the Ge0.9Sb0.1Te1.03 reaches a maximum zT value of ∼1.9 at 760 K and a giant average zT of ∼1.2 between 300 K and 820 K, which is comparable to the reported results for GeTe based materials. Combined with the rapid fabrication, Ge0.9Sb0.1Te1+x prepared by Melt Spinning process is an attractive p-type material for thermoelectric power generation application.
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improving thermoelectric performance of p type ag doped mg2si0 4sn0 6 prepared by unique Melt Spinning method
Applied Thermal Engineering, 2017Co-Authors: Guoyu Wang, Kunling Peng, Xiaodan Tang, Yong Zheng, Yumeng Zhang, Shuxia Wang, Tianyu Huang, Xiaoyuan ZhouAbstract:Abstract In our work, p-type Mg2−xAgxSi0.4Sn0.6 (x = 0.00, 0.01, 0.02, 0.05, 0.07) compounds with single-phase are successfully synthesized via a home-made Melt Spinning (MS) system followed by spark plasma sintering (SPS). This unique process not only largely shortens the time of sample preparation compared with the traditional methods, but also successfully prevents the presence of MgO impurity phase. All samples are single-phase solid solutions with an anti-fluorite structure as identified by XRD. The thermoelectric properties of Mg2−xAgxSi0.4Sn0.6 compounds were measured from room temperature to 773 K. The final results indicate that (1) Ag serves as effective holes donor and (2) the electrical conductivity rises rapidly and the thermal conductivity decreases with increasing Ag content until x = 0.05. As a result, a peak dimensionless figure of merit ZT value of 0.45 at 690 K is achieved when x = 0.05. The enhanced thermoelectric performance coupled with the drastically reduced processing time will be of considerable significance to the commercial-scale production of Mg2X (X = Si, Ge, and Sn) thermoelectric material.
Xiaodan Tang - One of the best experts on this subject based on the ideXlab platform.
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improving thermoelectric performance of p type ag doped mg2si0 4sn0 6 prepared by unique Melt Spinning method
Applied Thermal Engineering, 2017Co-Authors: Guoyu Wang, Kunling Peng, Xiaodan Tang, Yong Zheng, Yumeng Zhang, Shuxia Wang, Tianyu Huang, Xiaoyuan ZhouAbstract:Abstract In our work, p-type Mg2−xAgxSi0.4Sn0.6 (x = 0.00, 0.01, 0.02, 0.05, 0.07) compounds with single-phase are successfully synthesized via a home-made Melt Spinning (MS) system followed by spark plasma sintering (SPS). This unique process not only largely shortens the time of sample preparation compared with the traditional methods, but also successfully prevents the presence of MgO impurity phase. All samples are single-phase solid solutions with an anti-fluorite structure as identified by XRD. The thermoelectric properties of Mg2−xAgxSi0.4Sn0.6 compounds were measured from room temperature to 773 K. The final results indicate that (1) Ag serves as effective holes donor and (2) the electrical conductivity rises rapidly and the thermal conductivity decreases with increasing Ag content until x = 0.05. As a result, a peak dimensionless figure of merit ZT value of 0.45 at 690 K is achieved when x = 0.05. The enhanced thermoelectric performance coupled with the drastically reduced processing time will be of considerable significance to the commercial-scale production of Mg2X (X = Si, Ge, and Sn) thermoelectric material.
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Melt Spinning synthesis of p type skutterudites drastically speed up the process of high performance thermoelectrics
Scripta Materialia, 2016Co-Authors: Lijie Guo, Guiwen Wang, Kunling Peng, Yanci Yan, Xiaodan Tang, Min Zeng, Jiyan Dai, Guoyu WangAbstract:In this study, via a home-made induction Melting process combined with spark plasma sintering technique, we successfully synthesize the nanostructured skutterudites NdxYbyFe3CoSb12 (x + y = 1.0, x = 0.3, 0.4, 0.5, 0.6, 0.7) in less than 3 h, which is significantly faster than that of the solid state reaction (168 h) and the traditional Melt Spinning method (40 h). Systematical microstructures analysis of the sintered bulk materials reveals the largely refined matrix grains (100–300 nm) and ubiquitous YbSb precipitates (~ 30 nm), resulting in a very low lattice thermal conductivity. A peak ZT up to 1.02 at 760 K is obtained for Nd0.6Yb0.4Fe3CoSb12 compound.
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ultra rapid fabrication of p type li doped mg2si0 4sn0 6 synthesized by unique Melt Spinning method
Scripta Materialia, 2016Co-Authors: Lijie Guo, Guiwen Wang, Kunling Peng, Xiaodan Tang, Yong Zheng, Yumeng Zhang, Shuxia Wang, Min ZengAbstract:Abstract In this work, we successfully synthesized p -type Mg 2(1-x) Li 2x Si 0.4 Sn 0.6 (x = 0.00, 0.01, 0.03, 0.07, 0.09) samples using a home-made Melt Spinning system combined with spark plasma sintering. Compared with the samples prepared by a traditional method, the processing time is reduced from typically several days to less than one hour. It is found that the electrical conductivity rises rapidly with the increase of Li content owing to the enhanced carrier density, while the Seebeck coefficient decreases concomitantly to some extent. Meanwhile, Li doping dramatically reduces the thermal conductivity, leading to an enhanced figure of merit ZT ~ 0.58 at 760 K.
Lei Xie - One of the best experts on this subject based on the ideXlab platform.
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significant improvement of soft magnetic properties for fe based nanocrystalline alloys by inhibiting surface crystallization via a magnetic field assisted Melt Spinning process
Journal of Magnetism and Magnetic Materials, 2019Co-Authors: Lei Xie, Anding Wang, Shiqiang Yue, Chuntao Chang, Xinmin Wang, C T LiuAbstract:Abstract Fe-based soft-magnetic amorphous and nanocrystalline ribbons made with a single-side fast-cooling process always suffer from the surface crystallization which deteriorates the magnetic properties and inhibits the wide applications. In this study, a static magnetic field assisted Melt-Spinning process was employed to prepare the typical Fe84.75Si2B9P3C0.5Cu0.75 alloy ribbon with an attractive application prospect. According to the comparative investigations of the crystallization behavior, structural evolution process and magnetic properties, it is found that the applied magnetic field can effectively inhibit the formation of compound phases and decrease the size of textured α-Fe grains in the surface layer of the as-spun ribbon. The Fe84.75Si2B9P3C0.5Cu0.75 samples made with low purity raw materials and under an optimal field exhibit superior magnetic properties, including a high saturation magnetization (Bs) over 1.82 T, low coercivity (Hc) of 8.5 A/m, high permeability (μ) of 2.76 × 104 at 1 kHz and much lower losses, after nanocrystallization by annealing. The apparent effect of the applied magnetic field was discussed from the disturbance of a Lorentz force of the fast-moving molten alloy and a magnetic force of preformed grains in a magnetic field during the Melt-Spinning process. These results provide a novel solution of surface crystallization and an effective route for improving magnetic properties of Fe-based amorphous and nanocrystalline alloy ribbons.
Guoyu Wang - One of the best experts on this subject based on the ideXlab platform.
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synergistic effect of bismuth and indium codoping for high thermoelectric performance of Melt Spinning snte alloys
ACS Applied Materials & Interfaces, 2019Co-Authors: Huan Tan, Bin Zhang, Guoyu Wang, Xingchen Shen, Lijie Guo, Guiwen Wang, Xiao Zhang, Xiaoyuan ZhouAbstract:In this work, a nonequilibrium Melt Spinning (MS) technology combined with hot pressing was adopted for rapid synthesizing of SnTe compounds in less than 1 h. The refined microstructure generated by MS significantly decreases the lattice thermal conductivity. Compared to the pristine SnTe sample prepared by traditional Melting and long-term annealing, the Melt-spun one reveals a 15% lower thermal conductivity of ∼6.8 W/m K at room temperature and a 10% higher zT of ∼0.65 at 900 K. To further improve the electrical transport properties of the SnTe system, elements of Bi and In are introduced. It was found that Bi and In codoping can enhance Seebeck coefficients in a broad temperature range via optimizing carrier density and introducing resonant states. Point defects and nanoparticles introduced by Bi and In codoping remarkably enhanced phonon scattering and decreased lattice thermal conductivities. Finally, a significant enhancement on the thermoelectric performance was achieved: a peak zT of 1.26 at 900 K and an average zT of ∼0.48 over the temperature range of 300-900 K are obtained in Sn0.9675Bi0.03In0.0025Te. This work demonstrates that MS combined with appropriate doping could be an effective strategy to improve the thermoelectric performance of SnTe-related samples.
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rapid preparation of ge0 9sb0 1te1 x via unique Melt Spinning hierarchical microstructure and improved thermoelectric performance
Journal of Alloys and Compounds, 2019Co-Authors: Huan Tan, Bin Zhang, Guoyu Wang, Yongjin Chen, Xingchen Shen, Lijie Guo, Xiaodong Han, Xiaoyuan ZhouAbstract:Abstract Thermoelectric semiconductors based on GeTe has been proved to be an important materials for converting waste heat into electricity. In this study, we demonstrate an enhancement of thermoelectric performance for p-type Ge0.9Sb0.1Te1+x by a unique Melt Spinning method combined with hot pressing (MS-HP), through which increased Seebeck coefficients and reduced thermal conductivities are achieved simultaneously. Moreover, the MS technique greatly gives rise to a variety of microstructures, such as the fine Ge precipitates, twins and nano-domains, all of which contribute to the significantly reduced thermal conductivities. Finally, the Ge0.9Sb0.1Te1.03 reaches a maximum zT value of ∼1.9 at 760 K and a giant average zT of ∼1.2 between 300 K and 820 K, which is comparable to the reported results for GeTe based materials. Combined with the rapid fabrication, Ge0.9Sb0.1Te1+x prepared by Melt Spinning process is an attractive p-type material for thermoelectric power generation application.
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improving thermoelectric performance of p type ag doped mg2si0 4sn0 6 prepared by unique Melt Spinning method
Applied Thermal Engineering, 2017Co-Authors: Guoyu Wang, Kunling Peng, Xiaodan Tang, Yong Zheng, Yumeng Zhang, Shuxia Wang, Tianyu Huang, Xiaoyuan ZhouAbstract:Abstract In our work, p-type Mg2−xAgxSi0.4Sn0.6 (x = 0.00, 0.01, 0.02, 0.05, 0.07) compounds with single-phase are successfully synthesized via a home-made Melt Spinning (MS) system followed by spark plasma sintering (SPS). This unique process not only largely shortens the time of sample preparation compared with the traditional methods, but also successfully prevents the presence of MgO impurity phase. All samples are single-phase solid solutions with an anti-fluorite structure as identified by XRD. The thermoelectric properties of Mg2−xAgxSi0.4Sn0.6 compounds were measured from room temperature to 773 K. The final results indicate that (1) Ag serves as effective holes donor and (2) the electrical conductivity rises rapidly and the thermal conductivity decreases with increasing Ag content until x = 0.05. As a result, a peak dimensionless figure of merit ZT value of 0.45 at 690 K is achieved when x = 0.05. The enhanced thermoelectric performance coupled with the drastically reduced processing time will be of considerable significance to the commercial-scale production of Mg2X (X = Si, Ge, and Sn) thermoelectric material.
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Melt Spinning synthesis of p type skutterudites drastically speed up the process of high performance thermoelectrics
Scripta Materialia, 2016Co-Authors: Lijie Guo, Guiwen Wang, Kunling Peng, Yanci Yan, Xiaodan Tang, Min Zeng, Jiyan Dai, Guoyu WangAbstract:In this study, via a home-made induction Melting process combined with spark plasma sintering technique, we successfully synthesize the nanostructured skutterudites NdxYbyFe3CoSb12 (x + y = 1.0, x = 0.3, 0.4, 0.5, 0.6, 0.7) in less than 3 h, which is significantly faster than that of the solid state reaction (168 h) and the traditional Melt Spinning method (40 h). Systematical microstructures analysis of the sintered bulk materials reveals the largely refined matrix grains (100–300 nm) and ubiquitous YbSb precipitates (~ 30 nm), resulting in a very low lattice thermal conductivity. A peak ZT up to 1.02 at 760 K is obtained for Nd0.6Yb0.4Fe3CoSb12 compound.
Kunling Peng - One of the best experts on this subject based on the ideXlab platform.
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improving thermoelectric performance of p type ag doped mg2si0 4sn0 6 prepared by unique Melt Spinning method
Applied Thermal Engineering, 2017Co-Authors: Guoyu Wang, Kunling Peng, Xiaodan Tang, Yong Zheng, Yumeng Zhang, Shuxia Wang, Tianyu Huang, Xiaoyuan ZhouAbstract:Abstract In our work, p-type Mg2−xAgxSi0.4Sn0.6 (x = 0.00, 0.01, 0.02, 0.05, 0.07) compounds with single-phase are successfully synthesized via a home-made Melt Spinning (MS) system followed by spark plasma sintering (SPS). This unique process not only largely shortens the time of sample preparation compared with the traditional methods, but also successfully prevents the presence of MgO impurity phase. All samples are single-phase solid solutions with an anti-fluorite structure as identified by XRD. The thermoelectric properties of Mg2−xAgxSi0.4Sn0.6 compounds were measured from room temperature to 773 K. The final results indicate that (1) Ag serves as effective holes donor and (2) the electrical conductivity rises rapidly and the thermal conductivity decreases with increasing Ag content until x = 0.05. As a result, a peak dimensionless figure of merit ZT value of 0.45 at 690 K is achieved when x = 0.05. The enhanced thermoelectric performance coupled with the drastically reduced processing time will be of considerable significance to the commercial-scale production of Mg2X (X = Si, Ge, and Sn) thermoelectric material.
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Melt Spinning synthesis of p type skutterudites drastically speed up the process of high performance thermoelectrics
Scripta Materialia, 2016Co-Authors: Lijie Guo, Guiwen Wang, Kunling Peng, Yanci Yan, Xiaodan Tang, Min Zeng, Jiyan Dai, Guoyu WangAbstract:In this study, via a home-made induction Melting process combined with spark plasma sintering technique, we successfully synthesize the nanostructured skutterudites NdxYbyFe3CoSb12 (x + y = 1.0, x = 0.3, 0.4, 0.5, 0.6, 0.7) in less than 3 h, which is significantly faster than that of the solid state reaction (168 h) and the traditional Melt Spinning method (40 h). Systematical microstructures analysis of the sintered bulk materials reveals the largely refined matrix grains (100–300 nm) and ubiquitous YbSb precipitates (~ 30 nm), resulting in a very low lattice thermal conductivity. A peak ZT up to 1.02 at 760 K is obtained for Nd0.6Yb0.4Fe3CoSb12 compound.
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ultra rapid fabrication of p type li doped mg2si0 4sn0 6 synthesized by unique Melt Spinning method
Scripta Materialia, 2016Co-Authors: Lijie Guo, Guiwen Wang, Kunling Peng, Xiaodan Tang, Yong Zheng, Yumeng Zhang, Shuxia Wang, Min ZengAbstract:Abstract In this work, we successfully synthesized p -type Mg 2(1-x) Li 2x Si 0.4 Sn 0.6 (x = 0.00, 0.01, 0.03, 0.07, 0.09) samples using a home-made Melt Spinning system combined with spark plasma sintering. Compared with the samples prepared by a traditional method, the processing time is reduced from typically several days to less than one hour. It is found that the electrical conductivity rises rapidly with the increase of Li content owing to the enhanced carrier density, while the Seebeck coefficient decreases concomitantly to some extent. Meanwhile, Li doping dramatically reduces the thermal conductivity, leading to an enhanced figure of merit ZT ~ 0.58 at 760 K.