Atomic-scale tunable phonon transport at tailored grain boundaries

• DOI: 10.48550/arxiv.2405.07464
• Publication Date: 2024-05-13
• Authors: Xiaowang Wang; Chaitanya Gadre; Runqing Yang; W. X. Zou; Bin Xing; Christopher Addiego; Toshihiro Aoki; Yujie Quan; Wei-Tao Peng; Yifeng Huang; Chaojie Du; Mingjie Xu; Xingxu Yan; Ruqian Wu; Shyue Ping Ong; Bolin Liao; Penghui Cao; Xiaoqing Pan
• Keywords: Atomic units

Manipulating thermal properties in materials has been of fundamental importance for advancing innovative technologies. Heat carriers such as phonons are impeded by breaking crystal symmetry or periodicity. Notable methods impeding the phonon propagation include varying density defects, interfaces, and nanostructures, well changing composition. However, a robust link between individual nanoscale defect structures, states, macroscopic conductivity is lacking. Here we reveal from structure-phonon mechanisms on how grain boundary (GB) tilt twist angles fundamentally drive changes atom rearrangements, exotic vibrational finally heat transport at different bicrystal strontium titanate GBs using emerging atomic resolution spectroscopy. The 10 deg 22 exhibit reduced populations 54% 16% compared to bulk value, respectively, consistent with measured conductivities. A tiny angle further introduces fine local tunning introducing induced defects periodically embedded GB defects. Our results demonstrate that coarsely modifies population along entire while incurs finer adjustment periodic locations GB. study offers systematic approach understanding manipulating cross arbitrary predictably precisely.