Nanoscale characterization of crystalline and amorphous phases in silicon oxycarbide ceramics using 4D-STEM
Nanoscale characterization of crystalline and amorphous phases in silicon oxycarbide ceramics using 4D-STEM
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DOI：
10.1016/j.matchar.2021.111512
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发表时间：
2021-11
影响因子：
4.7
通讯作者：
N. Yang;C. Ophus;B. Savitzky;M. Scott;K. Bustillo;K. Lu
中科院分区：
文献类型：
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作者：
N. Yang;C. Ophus;B. Savitzky;M. Scott;K. Bustillo;K. Lu
聚合物衍生陶瓷在各种高温领域具有巨大的应用潜力。然而，缺乏原子尺度的表征和对中短程有序和无序的理解阻碍了这一有前途的材料家族的发展。本研究以聚（乙烯基甲基硅氧烷）衍生的碳化硅（SiOC）为模型体系来解决这一问题。基于电子衍射的径向分布函数（RDF）分析用于表征SiOC体系的中短阶，并提供分辨率为几纳米的局部结构数据。通过系统的数据校准和结构分析，通过基于python的py4DSTEM工具包记录和分析每个探针位置衍射图案的集成二维图像；得到了非晶+晶SiOC的相分布。这种方法提供了原子水平的表征，可以促进我们对SiOC形成和微观结构演化的基本理解。
Polymer-derived ceramics have great potentials in various high-temperature fields. However, lack of atomic-scale characterization and understanding of the short- to medium-range order and disorder hinders the advancement of this promising material family. In this study, poly(vinylmethylsiloxane)-derived silicon oxycarbide (SiOC) is used as a model system to address this issue. Electron diffraction-based radial distribution function (RDF) analysis is used to characterize the short- to medium-range order in the SiOC system and provide local structural data with a resolution of a few nanometers. With systematic data calibration and structural analysis, integrated 2D images from the diffraction pattern at each probe position are recorded and analyzed by the Python-based py4DSTEM toolkit; phase distributions of heterogeneous amorphous plus crystalline SiOC are obtained. This approach provides atomic-level characterization and can advance our fundamental understanding of the SiOC formation and microstructure evolution.