Correlative multimodal probing of ionically-mediated electromechanical phenomena in simple oxides

Abstract

The local interplay between the ionic and electronic transport in NiO is explored using correlative imaging by first-order reversal curve measurements in current-voltage and electrochemical strain microscopy. Electronic current and electromechanical response are observed in reversible and electroforming regime. These studies provide insight into local mechanisms of electroresistive phenomena in NiO and establish universal method to study interplay between the ionic and electronic transport and electrochemical transformations in mixed electronic-ionic conductors.

Figure 1

ESM (a) amplitude and (b) phase images. (c) Selected ESM hysteresis loops as measured at different locations. (d) Topography and spatial maps of (e) work of switching (area under the loop) and (f) imprint (difference between x-intercepts). Scale bar is 200 nm.

Figure 2. Average FORC type (a) I-V and (b) ESM loops as a function of varying bias (c); (d) corresponding loop area averaged over 1600 spatial points.

Figure 3. Spatial maps of (a, d) ESM loop area, (b, e) negative I-V loop area, and (c, f) positive I-V loop area for (a–c) 8 V and (d–f) 12 V, respectively.

Scale bar is 200 nm.

Figure 4. Correlation between ESM loop area and I-V loop area spatial maps for (a) negative and (b) positive biases.

Figure 5. Average FORC type (a, d) I-V and (b, e) ESM loops and (c, f) corresponding loop areas for (a–c) 10 points without any changes in surface state and (d–f) subsequent 1600 points including electroforming.

Figure 6. Spatial maps of (a, d) negative I-V loop area, (b, e) positive I-V loop area, and (c, f) ESM loop area for (a–c) 2 V and (d–f) 14 V, respectively.

Correlation between ESM loop area and I-V loop area for (g) negative and (h) positive biases.