Scanning Thermo-ionic Microscopy: Probing Nanoscale Electrochemistry via Thermal Stress-induced Oscillation

A universal challenge facing the development of electrochemical materials is our lack of understanding of physical and chemical processes at local length scales in 10-100 nm regime, and acquiring this understanding requires a new generation of imaging techniques. In this article, we introduce the scanning thermo-ionic microscopy (STIM) for probing local electrochemistry at the nanoscale, using for imaging the Vegard strain induced via thermal stress excitations. Since ionic oscillation is driven by the stress instead of voltage, the responses are insensitive to the electromechanical, electrostatic, and capacitive effects, and they are immune to global current perturbation, making in-operando testing possible.