Applications of the Lithium Focused Ion Beam: Nanoscale Electrochemistry and Microdisk Mode Imaging

The NIST-developed lithium Focused-Ion-Beam (LiFIB) system creates a low-energy, picoampere-scale ion beam from a photoionized gas of laser-cooled atoms. The ion beam can be focused to a <30 nm spot and scanned across a sample. This enables imaging through collection of ion-induced secondary electrons (similar to SEM) as well as the ability to selectively deposit lithium-ions into nanoscale volumes in a material. We exploit this second ability of the LiFIB to selectively "titrate" lithium ions as a means of probing the optical modes in microdisk resonators as well as for exploring nanoscale, Li-ion electrochemistry in battery-relevant materials. We present an overview of both measurements, including imaging of the optical mode in a silicon microdisk and a comparison of FIB and electrochemical lithiation of tin.