  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 in many materials 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.
