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Mg_2Si同质纳微米复合材料的制备及其热电性能 张联盟1,罗卫军1,杨梅君1,沈强1 (1.武汉理工大学,材料复合新技术国家重点实验室,湖北,武汉,430070) 摘要:以平均晶粒尺寸约3μm及20 nm的Mg_2Si粉末为原料,采用放电等离子体烧结方法制备出不同纳米,微米含量的Mg_2Si纳微米复合块体材料,系统研究了纳微米结构对材料热电性能的影响.结果表明:随复合材料中纳米颗粒含量的增加,晶界散射增强,导致材料晶格热导率κ_p有明显降低;同时晶界势垒散射的增强也导致Seebeck系数α显著增加,电导率σ有一定程度的降低;综合Seebeck系数α,电导率σ,热导率κ的影响,在纳米颗粒含量为50%(质量分数,下同),823 K时,获得最大热电优值达0.45,分别是未掺杂纳米相和完全纳米相Mg_2Si材料的1.5及1.1倍.纳微米复合结构的引入,可以获得性能更好的Mg_2Si热电材......
SPS法制备n-型Ag掺杂四元Ag-Bi-Se-Te 合金及其热电性能 应鹏展1,薛海峰1,崔教林2,修伟杰1 (1.中国矿业大学,江苏,徐州221008;2.宁波工程学院,浙江,宁波315016) 摘要:采用放电等离子烧结(SPS)方法制备Ag掺杂四元Ag-Bi-Se-Te合金,并分析研究其热电性能.结果表明:掺杂Ag后,合金AgxBi(2-x)Se0.3Te2.7(x=0.005~0.04)的Seebeck系数均为负值,说明材料属于n-型半导体;当温度大约在428.0K时,x=0.04合金的Seebeck系数绝对值(|a|)出现最大值,其值为1.80×10-4V·K-1,比三元合金Bi2Se0.3Te2.7的最大值增大约16%;材料电导率随Ag含量的增加而下降.如果采用相同方法制备且成分按(Bi2Te3)0.9-(Bi2-xAgxSe3)0.1(x=0~0.4)设计的材料热扩散......
FeTe2化合物快速制备及电学输运性能秦丙克1,2,籍永华2,宿太超3,白志玲2,黄润1,张金柱11. 贵州大学2. 六盘水师范学院3. 河南理工大学摘 要:利用真空高温烧结的方法,在803.15~923.15 K的温度范围内快速合成了单相的合金化合物FeTe2.在制备温度为863.15 K时,考查了不同保温时间对制备单相样品FeTe2的影响规律.制备出的样品进行了XRD和SEM分析,并在室温下对样品进行了电阻率和Seebeck系数的测试分析.结果表明:在803.15~923.15 K的温度范围内,采用高温烧结反应能够快速制备出单相的多晶体化合物FeTe2;制备出样品内部均匀存在许多微米级的孔洞.经室温电学性质测试,样品在制备温度为863.15 K保温时间60 min时获得最大Seebeck系数......
are significantly improved by vacuum annealing of NiCr and NiSi films. The variation of the Seebeck coefficient of TFTC was discussed based on the size effect of NiCr and NiSi films. And a lower Seebeck......
and Seebeck coefficient of the complex oxides were measured from 300 to 1073 K. The results showed that all the sam- ples were p-type semiconductors. The electrical conductivity increased with the increase in temperature. Er substitutions at Ca site affected carrier concentrations and carrier mobility, resulting an increase in Seebeck coefficient and decrease in electrical conductivity. The power......
a solid-state reaction followed by suitable cooling,annealing,grinding,and spark plasma sintering(SPS) densification processes.For samples with x=0.2,0.4,0.5,0.6,0.8,the electrical conductivity,Seebeck... the thermal conductivity at low temperature,while the electrical resistivity and the Seebeck coefficient in the compounds were found to increase with increasing Ca concentration.As a result,the dimensionless......
electron microscopy.The electrical resistivities and Seebeck coefficients of those samples were measured in the temperature range of 300-723 K,and the samples of SmxCo4Sb12 showed n-type conduction.The Seebeck coefficient in absolute value of SmxCo4Sb12 increased with an increase of temperature and decreased with an increase of x.Among all the samples,Sm0.5Co4Sb12 showed the highest power factor......
, the electrical conductivity, Seebeck coefficient, and thermal conductivity were performed as a function of temperature from 300 to 650 K. It was found that chemical substitution of Mn failed to optimize... despite the fact that it enlarged the Seebeck coefficient and reduced the thermal conductivity synchronously.关键词:......
proved the metallic nature of these compounds. Post-DFT(BoltzTraP) calculations were carried out to explore their thermoelectric properties like electrical conductivities. Seebeck coefficient, electronic thermal conductivities and figure of merit. The highest Seebeck coefficient and figure of merit were found for YbAu among these compounds which are 105 μV/K and 0.285 respectively. All......
成型压力和掺杂对Na1.4Co2O4基材料性能的影响厉英1,马北越1,姜茂发1,王臻明21. 东北大学材料与冶金学院2. 首秦金属材料有限公司炼钢部摘 要:采用溶胶-凝胶法制备了Na位掺杂Sr和Li(掺杂量分别为0.1,0.2,0.3和0.4)的Na1.4Co2O4基热电材料,研究了成型压力和掺杂对Na1.4Co2O4基材料电导率,Seebeck系数和功率因子等热电性能的影响.采用XRD分析了NaxCo2O4基热电材料的相组成.研究结果表明:掺杂Sr和Li制备的Na1.4Co2O4基材料的主晶相均为γ-Na1.4Co2O4;增加成型压力及掺杂Li均可明显提高材料的电导率,Seebeck系数和功率因子;当Li掺杂量为0.4时,在310 MPa下制备的Na1.4Co2O4基材料的功率因子为7.44......
