Approaching the Minimum Thermal Conductivity in Rhenium-Substituted Higher Manganese Silicides
Approaching the Minimum Thermal Conductivity in Rhenium-Substituted Higher Manganese Silicides
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DOI：
10.1002/aenm.201400452
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发表时间：
2014-10-07
影响因子：
27.8
通讯作者：
Shi, Li
中科院分区：
文献类型：
--
作者：
Chen, Xi;Girard, Steven N.;Shi, Li
由地球上丰富的无毒元素制成的高锰硅化物（HMS）由于其复杂的晶体结构导致晶格导热系数低而被认为是有前途的p型热电材料。研究表明，通过用较重的铼（Re）部分取代Mn来增加点缺陷散射，HMS的低导热系数可以进一步降低到接近最小导热系数。Re在所得RexMn1-xSi1.8中的溶解度极限约为x = 0.18。在HMS基体中发现了元素不均匀性和尺寸为50 ~ 200nm的ReSi1.75包裹体的形成。结果表明，在低稀土含量时，功率因数变化不明显
Higher manganese silicides (HMS) made of earth-abundant and non-toxic elements are regarded as promising p-type thermoelectric materials because their complex crystal structure results in low lattice thermal conductivity. It is shown here that the already low thermal conductivity of HMS can be reduced further to approach the minimum thermal conductivity via partial substitution of Mn with heavier rhenium (Re) to increase point defect scattering. The solubility limit of Re in the obtained RexMn1-xSi1.8 is determined to be about x = 0.18. Elemental inhomogeneity and the formation of ReSi1.75 inclusions with 50-200 nm size are found within the HMS matrix. It is found that the power factor does not change markedly at low Re content of x