The long-range periodic atomic arrangement or the lack thereof in solids typically dictates the magnitude and temperature dependence of their lattice thermal conductivity (κ_lat). Compared to crystalline materials, glasses exhibit a much-suppressed κ_lat across all temperatures as the phonon mean free path reaches parity with the interatomic distances therein. While the occurrence of such glass-like thermal transport in crystalline solids captivates the scientific community with its fundamental inquiry, it also holds the potential for profoundly impacting the field of thermoelectric energy conversion. Therefore, efficient manipulation of thermal transport and comprehension of the microscopic mechanisms dictating phonon scattering in crystalline solids are paramount. As quantized lattice vibrations (i.e., phonons) drive κ_lat, atomistic insights into the chemical bonding characteristics are crucial to have informed knowledge about their origins. Recently, it has been observed that within the highly symmetric ‘averaged’ crystal structures, often there are hidden locally asymmetric atomic motifs (within a few Å), which exert far-reaching influence on phonon transport. Phenomena such as local atomic off-centering, atomic rattling or tunneling, liquid-like atomic motion, site splitting, local ordering, etc., which arise within a few Å scales, are generally found to drastically disrupt the passage of heat carrying phonons. Despite their profound implication(s) for phonon dynamics, they are often overlooked by traditional crystallographic techniques. In this review, we provide a brief overview of the fundamental aspects of heat transport and explore the status quo of innately low thermally conductive crystalline solids, wherein the phonon dynamics is majorly governed by local structural phenomena. We also discuss advanced techniques capable of characterizing the crystal structure at the sub-atomic level. Subsequently, we delve into the emergent new ideas with examples linked to local crystal structure and lattice dynamics. While discussing the implications of the local structure for thermal conductivity, we provide the state-of-the-art examples of high-performance thermoelectric materials. Finally, we offer our viewpoint on the experimental and theoretical challenges, potential new paths, and the integration of novel strategies with material synthesis to achieve low κ_lat and realize high thermoelectric performance in crystalline solids via local structure designing.

中文翻译：

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隐藏结构：实现低热导率和高热电性能的驱动因素

固体中的长程周期性原子排列或缺乏这种排列通常决定了其晶格热导率 ( κ _lat ) 的大小和温度依赖性。与晶体材料相比，玻璃在所有温度下都表现出大大抑制的κ _lat，因为声子平均自由程达到了与其中原子间距离相同的水平。虽然晶体固体中发生的这种类似玻璃的热传输吸引了科学界的基础探究，但它也有可能对热电能量转换领域产生深远的影响。因此，有效控制热传输和理解晶体固体中声子散射的微观机制至关重要。由于量子化晶格振动（即声子）驱动κ _lat，对化学键特性的原子洞察对于了解其起源至关重要。最近，人们观察到，在高度对称的“平均”晶体结构中，往往隐藏着局部不对称的原子图案（几埃以内），这对声子输运产生了深远的影响。在几个 Å 尺度内出现的诸如局部原子偏心、原子震动或隧道、类液体原子运动、位点分裂、局部有序等现象通常被发现会极大地破坏载热声子的通道。尽管它们对声子动力学具有深远的影响，但它们经常被传统晶体学技术所忽视。在这篇综述中，我们简要概述了热传输的基本方面，并探讨了固有低导热性结晶固体的现状，其中声子动力学主要受局部结构现象控制。我们还讨论了能够在亚原子水平表征晶体结构的先进技术。随后，我们通过与局部晶体结构和晶格动力学相关的示例深入研究新兴的新想法。在讨论局部结构对导热性的影响时，我们提供了高性能热电材料的最先进示例。最后，我们对实验和理论挑战、潜在的新路径以及新策略与材料合成的整合提出了我们的观点，以通过局域结构设计实现低κ _lat并在晶体固体中实现高热电性能。