Conductive path and local oxygen-vacancy dynamics: Case study of crosshatched oxides

By employing scanning probe microscopy, conductive path and local oxygen-vacancy dynamics have been investigated in crosshatched La 0.7 Sr 0.3 MnO 3 thin films grown onto flat and vicinal LaAlO 3 (001) single crystal substrates. Consistent with prior studies, the crosshatch topography was observed first by dynamical force microscopy as the epi-stain started to release with increasing film thickness. Second, by using conductive atomic force microscopy (CAFM), conductive crosshatch and dots (locally aligned or random) were unravelled, however, not all of which necessarily coincided with that shown in the in situ atomic force microscopy. Furthermore, the current–voltage responses were probed by CAFM, revealing the occurrence of threshold and/or memristive switchings. Our results demonstrate that the resistive switching relies on the evolution of the local profile and concentration of oxygen vacancies, which, in the crosshatched films, are modulated by both the misfit and threading dislocations.