Real space mapping of oxygen vacancy diffusion and electrochemical transformations by hysteretic current reversal curve measurements

A system for mapping ionic diffusion or electrochemical reactivity comprising:

• a scanning probe operable to apply an electrical excitation voltage to each of one or more nanoscale volumes, wherein said electrical excitation voltage comprises one or more sweeps of a modulated voltage waveform and said modulated voltage waveform comprises cycles of increasing maximal amplitudes over time;
• a current detector which is operable to measure an electric current response induced by said electrical excitation voltage at each of said one or more nanoscale volumes;
• and
• one or more circuits which are operable to map reversal curves of said electric current response induced by said electrical excitation voltage, over a range of voltage which corresponds to said maximal amplitudes, for each of said cycles of increasing maximal amplitudes over time, to determine characteristics of said ionic diffusion or said electrochemical reactivity in said material;
• wherein said one or more circuits are operable to determine a spatial grid of locations on said material;
• said scanning probe is operable to apply said electrical excitation voltage to each of said one or more nanoscale volumes of said material, at each location of said spatial grid, wherein said electrical excitation voltage comprises said one or more sweeps of said modulated voltage waveform, and said modulated voltage waveform comprises said cycles of increasing maximal amplitudes over time;
• said current detector is operable to measure said electric current response induced by said electrical excitation voltage at each of said one or more nanoscale volumes of said material at each said location of said spatial grid;
• said one or more circuits are operable to determine an average reversal curve over said locations of said spatial grid, for each cycle of said modulated voltage waveform;
• and
• map said average reversal curves over said range of voltage which corresponds to said maximal amplitudes, for each cycle of said modulated voltage waveform.