Licata Olivia G, Broderick Scott R, Mazumder Baishakhi
Department of Materials Design and Innovation, University at Buffalo, Buffalo, NY14260, USA.
Microsc Microanal. 2020 Feb;26(1):95-101. doi: 10.1017/S1431927619015277.
In this work, the correlation between composition and relative evaporation field was investigated by tracking the statistics of multi-hit detector events in atom probe tomography (APT). This approach is applied systematically to a GaN-based nitride heterostructure with five AlxGa1-xN layers of varying Al composition. The relative field evaporation and the percentage of multi-hit events were found to increase with higher Al concentration. Furthermore, the comparison of the relative evaporation fields of AlN with respect to the constituent ions is found to be less than GaN with respect to its constituent ions. Despite equivalent compositions between opposing interfaces of the same AlxGa1-xN interlayer, the rate of change in multiplicity exhibits a consistent asymmetric trend with a steeper slope across the AlxGa1-xN/GaN interface compared to the GaN/AlxGa1-xN interface. The AlxGa1-xN/GaN heterostructure serves as a test structure for exploring field evaporation and neighborhood chemistry, which can be applied to any material chemistry and particularly other nitride systems.
在这项工作中，通过追踪原子探针断层扫描（APT）中多次命中探测器事件的统计数据，研究了成分与相对蒸发场之间的相关性。该方法被系统地应用于具有五个不同Al成分的AlxGa1-xN层的GaN基氮化物异质结构。发现相对场蒸发和多次命中事件的百分比随着Al浓度的增加而增加。此外，发现AlN相对于其组成离子的相对蒸发场与GaN相对于其组成离子的相对蒸发场相比要小。尽管同一AlxGa1-xN中间层的相对界面之间成分相同，但多重性的变化率呈现出一致的不对称趋势，与GaN/AlxGa1-xN界面相比，AlxGa1-xN/GaN界面处的斜率更陡。AlxGa1-xN/GaN异质结构用作探索场蒸发和邻域化学的测试结构，可应用于任何材料化学，特别是其他氮化物系统。
