Fu Le, Williams Jeromy, Micheletti Chiara, Lee Bryan E J, Xu Guofu, Huang Jiwu, Engqvist Håkan, Xia Wei, Grandfield Kathryn
School of Materials Science and Engineering, Central South University, Changsha 410083, China.
Department of Materials Science and Engineering, McMaster University, Hamilton, L8S 4L8 Ontario, Canada.
Nano Lett. 2021 Aug 25;21(16):6898-6906. doi: 10.1021/acs.nanolett.1c02051. Epub 2021 Aug 9.
The distribution of dopant atoms plays a key role in the effectiveness of doping, thereby requiring delicate characterizations. In this study, we found that energy-dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS) techniques in scanning transmission electron microscopy (STEM) were not adequate to reveal the distribution of yttrium and the chemical composition of the ZrO/SiO heterophase interface in an yttrium-doped ZrO-SiO nanocrystalline glass-ceramic. Atom probe tomography (APT) is rarely utilized to characterize ceramics due to some inherent difficulties. However, we successfully revealed the three-dimensional distribution of ZrO nanocrystallites and SiO matrix at the atomic scale with APT under optimized and well-controlled conditions. We also found that the ZrO nanocrystallites had a special core-shell structure, with a thin Zr/Si interfacial layer as a shell and a ZrO solid solution as a core. Yttrium dopants showed interfacial segregation at both ZrO grain boundaries and the ZrO/SiO heterophase interfaces.
掺杂原子的分布对掺杂效果起着关键作用，因此需要进行精细的表征。在本研究中，我们发现扫描透射电子显微镜（STEM）中的能量色散X射线光谱（EDX）和电子能量损失光谱（EELS）技术不足以揭示钇掺杂的ZrO-SiO纳米晶玻璃陶瓷中钇的分布以及ZrO/SiO异相界面的化学成分。由于一些固有困难，原子探针断层扫描（APT）很少用于表征陶瓷。然而，我们在优化和良好控制的条件下，利用APT成功地在原子尺度上揭示了ZrO纳米微晶和SiO基体的三维分布。我们还发现ZrO纳米微晶具有特殊的核壳结构，以薄的Zr/Si界面层为壳，以ZrO固溶体为核。钇掺杂剂在ZrO晶界和ZrO/SiO异相界面处均表现出界面偏析。
