Thermoelectric properties and Kondo transition in the pseudo-gap metals TiNiSi and TiNiGe
Thermoelectric properties and Kondo transition in the pseudo-gap metals TiNiSi and TiNiGe
复制标题
赝能隙金属 TiNiSi 和 TiNiGe 的热电性能和近藤跃迁
DOI：
10.1002/zaac.202300055
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Downie R
中科院分区：
文献类型：
--
作者：
Downie R
具有TiNiSi结构的材料最近被强调为潜在的热电材料。本文报道了TiNiX（X=Si和Ge）的热电性能。这两种材料都表现为有缺陷的金属或重掺杂的简并半导体。室温塞贝克系数为−45 μV K−1（Si）和−20 μV K−1（Ge），电阻率为0.5-1 mΩ cm。 360 K时的晶格热导率为8 W m-1 K-1（Si）和6 W m-1 K-1（Ge），这在没有合金化的情况下是有希望的。 计算的功率因数和品质因数仍然很小，在300 K附近，TiNiSi中最大的S2/ρ=0.17 mW m− 1 K − 2，峰值zT =5×10− 3。 这两种组合物在低温下都显示出与局部磁矩磁性的出现有关的近藤行为，并且在2 K下具有显著的磁阻效应。 这项工作提供了这一大类金属间化合物材料的两个成员的属性表征。
Materials with the TiNiSi structure have recently been highlighted as potential thermoelectric materials. Here we report the thermoelectric properties of TiNiX (X=Si and Ge). Both materials behave as defective metals or heavily doped degenerate semiconductors. Room temperature Seebeck coefficients are −45 μV K−1(Si) and −20 μV K−1(Ge) with electrical resistivities of 0.5–1 mΩ cm. The lattice thermal conductivities are 8 W m−1K−1(Si) and 6 W m−1K−1(Ge) at 360 K, which is promising in the absence of alloying. The calculated power factors and figures of merit remain small, with the largestS2/ρ=0.17 mW m−1K−2and peakzT=5×10−3seen in TiNiSi near 300 K. Both compositions show Kondo behaviour at low‐temperatures, linked to the emergence of local moment magnetism, and have substantial magnetoresistance effects at 2 K. This work provides property characterisation for two members of this large class of intermetallic materials.