Abstract Allotropy is a fundamental concept that has been frequently studied since the mid-1800s. Although the bulk allotropy of elemental solids is fairly well understood, it remains challenging to reliably produce an allotrope at the nanoscale that has a different crystal structure and accompanies a change in physical properties for specific applications. Here, we demonstrate a "heterostructure" approach to produce allotrope-like bismuth nanowires, where it utilizes the lattice constant difference between bismuth and tellurium in core/shell structure. We find that the resultant strain of [100]-grown Bi nanowires increases the atomic linear density along the c-axis that has been predicted from theoretical considerations, enabling us to establish a design rule for strain-induced allotropic transformation. With our >400-nm-diameter nanowires, we measure a thermoelectric figure of merit ZT of 0.5 at room temperature with reduced thermal conductivity and enhanced Seebeck coefficient, which are primarily a result of the rough interface and the reduced band overlap according to our density-functional calculations.

中文翻译：

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用于增强热电性能的应变工程同素异形体铋纳米线

摘要 自 1800 年代中期以来，同素异形体是一个经常被研究的基本概念。尽管元素固体的整体同素异形体已被很好地理解，但在纳米尺度上可靠地生产具有不同晶体结构并伴随特定应用物理性质变化的同素异形体仍然具有挑战性。在这里，我们展示了一种“异质结构”方法来生产类似同素异形体的铋纳米线，它利用核/壳结构中铋和碲之间的晶格常数差异。我们发现 [100] 生长的 Bi 纳米线的合成应变增加了从理论考虑预测的沿 c 轴的原子线密度，使我们能够建立应变诱导同素异形转变的设计规则。随着我们的 >