Scanning thermo-ionic microscopy for probing local electrochemistry at the nanoscale
| Autor: | Ahmadreza Eshghinejad, Stuart B. Adler, Tim C. Geary, Shuhong Xie, Peiqi Wang, Ehsan Nasr Esfahani, Jiangyu Li |
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| Rok vydání: | 2016 |
| Předmět: |
Oscillation
Chemistry Capacitive sensing Analytical chemistry General Physics and Astronomy Ionic bonding 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Thermal expansion 0104 chemical sciences Characterization (materials science) Microscopy Grain boundary 0210 nano-technology Nanoscopic scale |
| Zdroj: | Journal of Applied Physics. 119:205110 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | Conventional electrochemical characterization techniques based on voltage and current measurements only probe faradaic and capacitive rates in aggregate. In this work we develop a scanning thermo-ionic microscopy (STIM) to probe local electrochemistry at the nanoscale, based on imaging of Vegard strain induced by thermal oscillation. It is demonstrated from both theoretical analysis and experimental validation that the second harmonic response of thermally induced cantilever vibration, associated with thermal expansion, is present in all solids, whereas the fourth harmonic response, caused by local transport of mobile species, is only present in ionic materials. The origin of STIM response is further confirmed by its reduced amplitude with respect to increased contact force, due to the coupling of stress to concentration of ionic species and/or electronic defects. The technique has been applied to probe Sm-doped Ceria and LiFePO4, both of which exhibit higher concentrations of mobile species near grain bo... |
| Databáze: | OpenAIRE |
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