Application of high-spatial-resolution secondary ion mass spectrometry for nanoscale chemical mapping of lithium in an Al-Li alloy

• Published in: Materials characterization Vol. 181; p. 111442
• Main Authors: Xu, Xu, Jiao, Chengge, Li, Kexue, Hao, Min, Moore, Katie.L., Burnett, Timothy.L., Zhou, Xiaorong
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-11-2021
• Subjects: Aluminium-lithium alloy; FIB ToF-SIMS; High-spatial-resolution secondary ion mass spectrometry; Nanoscale mapping of lithium; NanoSIMS; NanoSIMS; Aluminium-lithium alloy; High-spatial-resolution secondary ion mass spectrometry; Nanoscale mapping of lithium; FIB ToF-SIMS
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2021.111442

High-spatial-resolution secondary ion mass spectrometry offers a method for mapping lithium at nanoscale lateral resolution. Practical implementation of this technique offers significant potential for revealing the distribution of Li-containing nanoscale precipitates in Al-Li alloys with exceptional lateral resolution and elemental sensitivity. Here, two state-of-the-art methods are demonstrated on an aluminium-lithium alloy to visualise nanoscale Li-rich phases by mapping the 7Li+ secondary ion. NanoSIMS 50L analysis with a radio frequency O− plasma ion source enabled visualisation of needle-shaped T1 (Al2CuLi) phases as small as 75 nm in width. A compact time-of-flight secondary ion mass spectrometry detector added to a focused ion beam scanning electron microscope facilitated mapping of the T1 phases down to 45 nm in width using a Ga+ ion beam. Correlation with high resolution electron microscopy confirms the identification of T1 precipitates, their sizes and distribution observed during SIMS mapping.
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•High-lateral-resolution SIMS was used to characterise Li distribution in nanoscale.•The observations from SIMS were validated using correlative electron microscopy.•NanoSIMS visualises Li-rich T1 (Al2CuLi) phases as small as 75 nm in size.•FIB ToF-SIMS visualises intergranular T1 precipitates as small as 45 nm in size.•STEM-EDX analysis provides complementary information of phase chemistry.