Gao Hanbin, Guo Ning, Gong Yue, Bai Lu, Wang Dongwei, Zheng Qiang
Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450003, China.
CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
Nanoscale. 2023 Dec 14;15(48):19469-19474. doi: 10.1039/d3nr05176e.
High-entropy oxides (HEOs) are a special class of materials that utilize the concept of high-entropy alloys (HEAs) with five or more elements randomly distributing at a single sublattice in near-equiatomic proportions. HEOs have been attracting increasing attention owing to their many outstanding physical and chemical properties. However, unlike HEAs, for which local chemical compositions, order/disorder behaviors, and property-structure relationships have been comprehensively investigated, detailed information on the atomic-scale chemical and structural features and their correlations with functionalities in HEOs so far is still not sufficient. Herein, we select four typical HEOs with pyrochlore, spinel, perovskite and rock-salt type structures, and directly observe and quantify sub-Ångstrom-scale structure variations in different manners by means of advanced aberration-corrected scanning transmission electron microscopy techniques. Visualization and quantification of local structural variations and lattice distortions in the current work may show a valuable example for future investigations on local fluctuating structures and their relationships with properties in more systems of HEOs.
高熵氧化物（HEOs）是一类特殊的材料，它利用了高熵合金（HEAs）的概念，即五种或更多种元素以近等原子比例随机分布在单个亚晶格中。由于其许多优异的物理和化学性质，高熵氧化物一直吸引着越来越多的关注。然而，与已经对其局部化学成分、有序/无序行为以及性能-结构关系进行了全面研究的高熵合金不同，迄今为止，关于高熵氧化物中原子尺度的化学和结构特征及其与功能的相关性的详细信息仍然不足。在此，我们选择了具有烧绿石、尖晶石、钙钛矿和岩盐型结构的四种典型高熵氧化物，并通过先进的像差校正扫描透射电子显微镜技术以不同方式直接观察和量化亚埃尺度的结构变化。当前工作中对局部结构变化和晶格畸变的可视化和量化可能为未来在更多高熵氧化物体系中研究局部波动结构及其与性能的关系提供一个有价值的范例。
