Sen Amrita, Bachhav Mukesh, Vurpillot Francois, Mann J Matthew, Morgan Phyllis K, Prusnick Timothy A, Wharry Janelle P
Flex Lab, Purdue University, 205 Gates Road, West Lafayette, IN 47906, United States.
Advanced Characterization Department, Idaho National Laboratory, P.O. Box 1625, MS 6188, Idaho Falls, Idaho 83415, United States.
Ultramicroscopy. 2021 Jan;220:113167. doi: 10.1016/j.ultramic.2020.113167. Epub 2020 Nov 9.
Atom probe tomography (APT), a 3D microscopy technique, has great potential to reveal atomic scale compositional variations, such as those associated with irradiation damage. However, obtaining accurate compositional quantification by APT for high bandgap materials is a longstanding challenge, given the sensitivity to field evaporation parameters and inconsistent behaviors across different oxides. This study investigates the influence of APT laser energy and specimen base temperature on compositional accuracy in single crystal thoria (ThO). ThO has a broad range of applications, including advanced nuclear fuels, sensors, lasers and scintillators, electrodes, catalysis, and photonics and optoelectronics. The expected stoichiometry of ThO is achieved at APT base temperature of 24 K and laser energy of 100 pJ. To overcome mass resolution limitations associated with significant thermal tails, Bayesian methods are applied to deconvolute ion identity within the mass spectra. This approach affirms that the parameters chosen are appropriate for APT analysis of ThO.
原子探针断层扫描（APT）是一种三维显微镜技术，在揭示原子尺度的成分变化方面具有巨大潜力，例如与辐照损伤相关的变化。然而，鉴于对场蒸发参数的敏感性以及不同氧化物之间行为的不一致性，通过APT对高带隙材料进行准确的成分定量分析一直是一项长期挑战。本研究调查了APT激光能量和样品基底温度对单晶氧化钍（ThO）成分准确性的影响。氧化钍有广泛的应用，包括先进核燃料、传感器、激光器和闪烁体、电极、催化以及光子学和光电子学。在24K的APT基底温度和100 pJ的激光能量下可实现氧化钍的预期化学计量比。为克服与显著热尾相关的质量分辨率限制，采用贝叶斯方法对质谱内的离子身份进行反卷积。该方法证实所选择的参数适用于氧化钍的APT分析。
