发表机构
Shanghai Jiao Tong University; Institute of High Energy Physics, Chinese Academy of Sciences; Spallation Neutron Source Science Center; Guangdong Provincial Key Laboratory of Extreme Conditions; Great Bay University; Shanghai University; National Synchrotron Radiation Research Center; China Jiliang University; Jilin University; Shanghai Institute of Ceramics, Chinese Academy of Sciences（上海交通大学; 中国科学院高能物理研究所; 散裂中子源科学中心; 广东省极端条件重点实验室; 大湾区大学; 上海大学; 国家同步辐射研究中心; 中国计量大学; 吉林大学; 中国科学院上海陶瓷研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过掺杂剂诱导的晶格刚度调制，在β-FeSi2中实现了晶格热导率的大幅降低（Co掺杂在300 K时约71%），确立了晶格软化作为热电材料热管理的新策略。
AI 中文摘要
抑制晶格热导率（κlat）对于热电效率至关重要。虽然传统策略主要依赖于质量和尺寸失配引起的声子散射，但我们展示了一种由掺杂诱导的晶格刚度调制驱动的稳健的κlat抑制机制。通过对β-FeSi2模型系统中p型（Mn）和n型（Co，Ir）掺杂的比较分析，我们表明Co和Ir掺杂显著降低了κlat。值得注意的是，即使在无明显质量和尺寸对比的情况下，Co掺杂在300 K时也实现了约71%的降低。通过将输运数据与中子粉末衍射、热容和拉曼光谱相关联，我们揭示了异常的晶格膨胀、德拜温度的显著降低以及明显的振动红移和展宽。这些系统性变化为原子尺度的晶格软化和原子间力常数的根本减弱提供了强有力的证据，这协同降低了声子群速度并增强了非谐散射。我们的发现确立了晶格刚度操控作为热管理的一种强大策略，提供了超越传统质量和应变涨落模型的独特设计途径。
英文摘要
Suppressing lattice thermal conductivity (K_lat) is pivotal for thermoelectric efficiency. While traditional strategies rely heavily on phonon scattering from mass- and size-mismatches, we demonstrate a robust K_lat suppression mechanism driven by dopant-induced lattice stiffness modulation. Through a comparative analysis of p-type (Mn) and n-type (Co, Ir) doping in the β-FeSi2 model system, we show that Co and Ir doping significantly reduce K_lat. Notably, Co doping achieves a ~71% reduction at 300 K even without significant mass and size contrast. By correlating transport data with neutron powder diffraction, heat capacity, and Raman spectroscopy, we reveal anomalous lattice expansion, a substantial reduction in Debye temperature, and marked vibrational redshift and broadening. These systematic changes provide strong evidence for atomic-scale lattice softening and a fundamental weakening of interatomic force constants, which synergistically lower phonon group velocities and amplify anharmonic scattering. Our findings establish lattice stiffness manipulation as a powerful strategy for thermal management, offering a distinct design pathway beyond traditional mass- and strain-fluctuation models.
Comments21 pages, 7 figures
Journal refQuantum Front 5, 9 (2026)
DOI：10.1007/s44214-026-00106-x
