Bi4SeCl2O4, has recently drawn significant interest for the reported extremely low thermal conductivity (κ), making it a promising material for thermoelectric applications. The anisotropy nature of this material allows for the manipulation of transport properties for optimization in a certain direction. However, there is still a lack of systematic research on the role of texturization in the thermal transport properties of Bi4SeCl2O4. In this work, single-phase polycrystalline Bi4SeCl2O4 was synthesized by solid-phase reaction and hot-pressing. The effect of both texturization and density on the thermal conductivity of Bi4SeCl2O4 was experimentally investigated in detail. The results show that once the density is higher than 80 %, this work demonstrates a κ of >0.4 W/m-K even when the orientation factor reaches ∼0.5. The κ was verified by different measurement techniques. In addition, the heat insulation performance of Bi4SeCl2O4 was found to be intermediate between that of PTFE and silica.

中文翻译：

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具有不同质构化和密度的多晶 Bi4SeCl2O4 的热传输特性


Bi4SeCl2O4 最近因报道的极低导热系数 （κ） 而引起了人们的极大兴趣，使其成为热电应用的一种有前途的材料。这种材料的各向异性特性允许操纵传输属性，以便在某个方向上进行优化。然而，对于织构化在 Bi4SeCl2O4 的热传输性能中的作用，仍然缺乏系统的研究。本工作通过固相反应和热压合成了单相多晶 Bi4SeCl2O4。实验详细研究了质构和密度对 Bi4SeCl2O4 热导率的影响。结果表明，一旦密度高于 80 %，这项工作表明，即使取向因子达到 ∼0.5，κ 也为 >0.4 W/m-K。κ 通过不同的测量技术进行了验证。此外，发现 Bi4SeCl2O4 的隔热性能介于 PTFE 和二氧化硅之间。