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1.
系统地研究了晶粒尺寸对CoSb3化合物热电性能的影响规律,结果表明晶粒尺寸对CoSb3化合物的晶格热导率κp、电导率σ、能隙宽度Eg和Seebeck系数α有显著影响.当晶粒尺寸由微米尺度减小到纳米尺度时,晶格热导率κp显著降低,Seebeck系数α有较大幅度的增加,能隙宽度Eg变宽,电导率σ有一定程度的下降.平均晶粒尺寸为200nm的CoSb3化合物在温度为700K时,ZT值达到0.43,比平均晶粒尺寸为5000nm的试样增加了4倍. 相似文献
2.
以Sb ,Co为起始原料 ,采用固相反应法合成了CoSb3.通过高能球磨制得CoSb3纳米粉末 ,用放电等离子烧结(SPS)方法制备出最小平均晶粒尺寸为 1 5 0nm的块体材料 .研究了晶粒尺寸与热传输性能之间的关系 :CoSb3化合物结构纳米化对其晶格热导率κL 有显著影响 ,当晶粒尺寸由微米尺度减小到纳米尺度 ,晶格热导率κL 显著降低 ,但对载流子热导率κc 的影响不甚显著 .CoSb3化合物的热导率κ随晶粒尺寸的减小而降低主要是由于晶格热导率κL 随晶粒尺寸的减小而降低所致 相似文献
3.
Effects of nano-TiO2 dispersion on the thermoelectric properties offilled-skutterudite Ba0.22Co4Sb12
Zhen Xiong Xihong Chen Xueying Zhao Shengqiang Bai Xiangyang Huang Lidong Chen 《Solid State Sciences》2009,11(9):1612-1616
Homogeneously dispersed nano-TiO2 was introduced into the matrix of n-type barium-filled cobalt antimony (Ba0.22Co4Sb12) via sol–gel method successfully. The Seebeck coefficients are improved and the lattice thermal conductivities are depressed with a proper addition of nano-TiO2 not more than 0.8 vol.%, while the electrical conductivities nearly remain unchanged. The effects of n-type semiconductive nanoscale inclusions on the electrical and thermal transport characteristics are discussed. Microstructure analyses indicate that the fine nanoinclusions locate on the grain boundaries as well as inside grains, which serve as extra phonon scattering mode and new type energy filtering. As a result, the optimal ZT value was achieved for the sample of 0.4 vol.% TiO2 composition. 相似文献
4.
New skutterudite compounds CaxCo4Sb12 (0<x?0.2) have been prepared by traditional metallurgical synthesis. The compounds have been characterized by X-ray powder diffraction (XRD), electron probe microanalysis (EPMA) and neutron powder diffraction. Rietveld refinement of the structures against neutron powder diffraction data (on Ca0.1Co4Sb12, , a=9.0429 Å, χ2=1.55; wRp=1.52) enabled the location of Ca in the voids of the skutterudite structure to be verified. The large displacement ellipsoid for Ca is consistent with “rattling” in the cage of the crystalline structure. XRD combined with EPMA analyses showed that the maximum occupancy of Ca atoms is about 0.2. 相似文献
5.
用两步固相反应法合成了p型Ba填充方钴矿化合物Ba0.3FeCo3S b12,并采用放电等离子烧结法(SPS)制备了Ba0.3FeCo3Sb12/多壁碳纳米管复合材料. 研究了Ba0.3FeCo3Sb12/多壁碳纳米管复合 材料的结构及多壁碳纳米管对 其热电性能的影响规律:SEM分析表明多壁碳纳米管比较均匀地分布在Ba0.3 FeCo3S b12基体中;随着碳纳米管添加量的增加,Ba0.3FeCo3Sb12/多壁碳 纳米管复合材料的电导率下降、塞贝克系数略微下降、晶格热导率大幅度降低,当碳纳米管 含量为5%时其晶格热导率最小;当碳纳米管的含量为3%时,本研究得到的Ba0.3 sup>FeCo3Sb12/碳纳米管复合材料的最大ZT值达078. 相似文献
6.
用两步固相反应法合成了P型Ba填充方钴矿化合物Ba0.3FeCo3Sb12,并采用放电等离子烧结法(SPS)制备了Ba0.3FeCo3Sb12/多壁碳纳米管复合材料.研究了Ba0.3FeCo3Sb12/多壁碳纳米管复合材料的结构及多壁碳纳米管对其热电性能的影响规律:SEM分析表明多壁碳纳米管比较均匀地分布在Ba0.3FeCo3Sb12基体中;随着碳纳米管添加量的增加,Ba0.3FeCo3Sb12/多壁碳纳米管复合材料的电导率下降、塞贝克系数略微下降、晶格热导率大幅度降低,当碳纳米管含量为5%时其晶格热导率最小;当碳纳米管的含量为3%时,本研究得到的Ba0.3FeCo3Sb12/碳纳米管复合材料的最大ZT值达0.78. 相似文献
7.
Skutterudite compounds PbxBayCo4Sb11.5Te0.5 (x≤0.23,y≤0.27) with bcc crystal structure have been prepared by the high pressure and high temperature (HPHT) method. The study explored a chemical method for filling Pb and Ba atoms into the voids of CoSb3 to optimize the thermoelectric figure of merit ZT in the system of PbyBaxCo4Sb11.5Te0.5. The structure of PbxBayCo4Sb11.5Te0.5 skutterudites was evaluated by means of X-ray diffraction. The Seebeck coefficient, electrical resistivity and power factor were performed from room temperature to 710 K. Compared with Co4Sb11.5Te0.5, the thermal conductivity of Pb and Ba double-filled samples was reduced evidently. Among all filled samples, Pb0.03Ba0.27Co4Sb11.5Te0.5 showed the highest power factor of 31.64 μW cm−1 K−2 at 663 K. Pb0.05Ba0.25Co4Sb11.5Te0.5 showed the lowest thermal conductivity of 2.73 W m−1 K−1 at 663 K, and its maximum ZT value reached 0.63 at 673 K. 相似文献
8.
D. Colceag A. Dauscher B. Lenoir R. Birjega M. Dinescu 《Applied Surface Science》2007,253(19):8097-8101
CaxCo4Sb12 skutterudite thin films have been prepared by pulsed laser deposition using a Nd:YAG laser working at 532 or 266 nm of wavelength. Characterization has been carried out by X-ray diffraction, atomic force microscopy and scanning electron microscopy. Emphasis has been put on the difficulty to obtain the skutterudite phase. Influence of the deposition temperature, the way of sticking the substrate, the laser fluence, the base pressure prior to deposition and the laser wavelength has been studied. All parameters revealed to have a drastic effect, and the skutterudite could only be achieved in a very narrow range of temperature and laser fluence, for a given wavelength, showing the importance on how these parameters are measured to ensure reproducible results. 相似文献
9.
Matthias Ikeda Petr Tomeš Lukas Prochaska James Eilertsen Sascha Populoh Stefan Löffler Robert Svagera Monika Waas Herbert Sassik Anke Weidenkaff Silke Paschen 《无机化学与普通化学杂志》2015,641(11):2020-2028
Nano‐grained CoSb3 was prepared by melt‐spinning and subsequent spark plasma sintering. The phonon thermal conductivity of skutterudites is known to be sensitive to the kind and the amount of guest atoms. Thus, unfilled CoSb3 can serve as model compound to study the impact of a nanostructure on the thermoelectric properties, especially the phonon thermal conductivity. Therefore, a series of materials was prepared differing only by the cooling speed during the quenching procedure. In contrast to clathrates, the microstructure of meltspun CoSb3 was found to be sensitive to the cooling speed. Although the phonon thermal conductivity, studied by means of Flash and 3ω measurements, was found to be correlated with the grain size, the bulk density of the sintered materials had an even stronger impact. Interestingly, the reduced bulk density did not result in an increased electrical resistivity. The influence of Sb and CoSb2 as foreign phase on the electronic properties of CoSb3 was revealed by a multi‐band Hall effect analysis. While CoSb2 increases the charge carrier density, the influence of the highly mobile charge carriers introduced by elemental Sb on the thermoelectric properties of the composite offer an interesting perspective for the preparation of efficient thermoelectric composite materials. 相似文献
10.
以Sb,Co为起始原料,采用固相反应法合成了CoSb3.通过高能球磨制得CoSb3纳米粉末,用放电等离子烧结(SPS)方法制备出最小平均晶粒尺寸为150nm的块体材料.研究了晶粒尺寸与热传输性能之间的关系:CoSb3化合物结构纳米化对其晶格热导率κL有显著影响,当晶粒尺寸由微米尺度减小到纳米尺度,晶格热导率κL显著降低,但对载流子热导率κc的影响不甚显著.CoSb3化合物的热导率κ随晶粒尺寸的减小而降 低主要是由于晶格热导率κL随晶粒尺寸的减小而降低所致.
关键词:
纳米
Skutterudite
制备
热传输特性 相似文献