The longitudinal thermal transport properties of composite multi-filamentary iron-based superconducting tapes are studied in magnetic fields up to 9 T. The Cu/Ag tape exhibits the highest thermal conductivity κ(4.2 K) = 440 W m −1 K −1 at 0 T, which remains above 100 W m −1 K −1 at 9 T. After applying different alloys as the outer sheath, the overall thermal conductivity is considerably decreased. We utilize the equivalent heat current circuit model to analyze the temperature dependence of κ. It is found that there exist two sources of diffusion into the inner Ag sheath: the doped Sn from the superconducting core and the elements from the outer sheath. It results in a suppressed thermal transport ability of the Ag sheath. Our studies provide insights and precautions for conductor designs for the future applications of iron-based superconducting wires and tapes.

中文翻译：

---

复合多丝铁基超导带的导热系数

在高达9 T的磁场中研究了复合多丝铁基超导带的纵向热传输特性。Cu/ Ag带在以下条件下表现出最高的导热率κ（4.2 K）= 440 W m -1 K -1 0 T，在9 T时仍保持在100 W m -1 K -1以上。在应用不同的合金作为外部护套后，整体导热系数大大降低。我们利用等效热电流电路模型来分析κ的温度依赖性。发现存在两个扩散到内部银皮中的来源：来自超导芯的掺杂锡和来自外部皮中的元素。这导致银护套的热传输能力受到抑制。