论文标题
使用ADF-STEM在几十张薄膜的分辨率下使用ADF-STEM表征钙钛矿和pyrochlore氧化物中的氧原子
Characterizing oxygen atoms in perovskite and pyrochlore oxides using ADF-STEM at a resolution of a few tens of picometers
论文作者
论文摘要
We present an aberration corrected scanning transmission electron microscopy (ac-STEM) analysis of the perovskite (LaFeO3) and pyrochlore (Yb2Ti2O7 and Pr2Zr2O7) oxides and demonstrate that both the shape and contrast of visible atomic columns in annular dark-field (ADF) images are sensitive to the presence of nearby atoms of low atomic number (e.g. oxygen).我们表明，在X射线和中子衍射测量中，这些点缺陷（例如氧空位）是看不见或由于灵敏度有限而难以观察的，是pyrochlore氧化物的复杂磁场状态的起源。此外，我们首次提出了一种可以在定量ADF-STEM图像中解析光原子的方法。使用这种方法，我们在钙钛矿和pyrochlore氧化物中解析了氧原子。
We present an aberration corrected scanning transmission electron microscopy (ac-STEM) analysis of the perovskite (LaFeO3) and pyrochlore (Yb2Ti2O7 and Pr2Zr2O7) oxides and demonstrate that both the shape and contrast of visible atomic columns in annular dark-field (ADF) images are sensitive to the presence of nearby atoms of low atomic number (e.g. oxygen). We show that point defects (e.g. oxygen vacancies), which are invisible - or difficult to observe due to limited sensitivity - in X-ray and neutron diffraction measurements, are the origin of the complex magnetic ground state of pyrochlore oxides. In addition, we present, for the first time, a method by which light atoms can be resolved in quantitative ADF-STEM images. Using this method, we resolved oxygen atoms in perovskite and pyrochlore oxides.
