论文标题
金纳米棒中的形状依赖性局部应变：数据驱动的原子分辨率电子显微镜分析
Shape-dependent local strain in gold nanorods: data-driven atomic-resolution electron microscopy analysis
论文作者
论文摘要
原子间距离或局部晶格菌株的局部变化通常会影响纳米颗粒的材料特性。最近的原子分辨率电子显微镜提供了约1％精度的应变测量。但是，精度受到实验数据中的噪音的限制。在这里，我们应用了一个数据驱动的分析之一，即高斯过程回归来预测菌株的真实形式。对于检测局部菌株的检测，该精度已提高到0.2％，以下是0.2％。已经揭示了杆状纳米颗粒在地下帽尖端区域周围包含特征性晶格膨胀〜+0.6％。实验结果通过相应形状模型的分子动力学模拟复制。纳米棒的菌株用曲率依赖性的非均匀表面应力来解释，这是由于形状各向异性而引起的。目前的结果带来了纳米级工程的提示，以通过形状控制优化纳米颗粒中的应变。
The local variation in inter-atomic distances, or local lattice strain often influences significantly material properties of nanoparticles. Strain measurement with ~1% precision is provided by recent atomic-resolution electron microscopy. However, the precision has been limited by noises in the experimental data. Here, we have applied one of the data-driven analyses, Gaussian process regression to predict true form of strain. The precision has been improved to be sub-percent of 0.2 % and more for detection of local strain. Rod-shaped nanoparticles have been revealed to contain characteristic lattice expansion ~+0.6 % around the subsurface cap tip area. The experimental results are reproduced by molecular dynamics simulations of the corresponding shaped atomic models. The strain peculiar to nanorods are explained in terms of curvature-dependent non-uniform surface stress due to shape anisotropy. The present results bring a hint to nanoscale engineering to optimize the strain in nanoparticles by shape control.
