Canadian Centre for Electron Microscopy and Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1.
Phys Chem Chem Phys. 2013 Jul 21;15(27):11420-6. doi: 10.1039/c3cp51135a. Epub 2013 Jun 7.
The ability to visualize and identify individual dopants, as well as measure their local physical and chemical environments in a bulk, provides deep insight for designing new functional materials and predicting their properties. However, a full understanding of dopants inside a solid has been limited by currently available characterization techniques. We demonstrate the first atomic-level 2-dimensional elemental maps of Pr dopants using the electron energy-loss spectroscopy (EELS) technique and we image Al dopants located in a lattice. Based on spectroscopic and imaging evidence we provide plausible local defect configurations of implanted Pr(+) and Al(+) ions within SrTiO3 single crystals. Our results demonstrate the detection of single Pr atoms and the formation of Al-rich nanoscale clusters ranging from 1 to 3 nm in size randomly distributed in the implanted lattice. These results provide insight into the mechanism of red light emission in doped SrTiO3.
能够在体相内对单个掺杂剂进行可视化和识别，并对其局部物理和化学环境进行测量，为设计新型功能材料和预测其性能提供了深入的认识。然而，由于目前可用的表征技术的限制，对固体内部掺杂剂的全面了解仍受到限制。我们利用电子能量损失谱（EELS）技术首次获得了 Pr 掺杂原子的二维元素图谱，并对位于晶格中的 Al 掺杂原子进行了成像。基于光谱和成像证据，我们提出了 SrTiO3 单晶中注入的 Pr(+)和 Al(+)离子的局部缺陷结构的合理模型。我们的结果表明，在注入的晶格中可以检测到单个 Pr 原子，并形成富 Al 的纳米级团簇，尺寸在 1 到 3nm 之间，随机分布。这些结果为掺杂 SrTiO3 中红光发射的机制提供了深入的了解。
