Figure - available from: Journal of Applied Physics
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Atomic models of four types of steps. (a) and (b) are neutral step models with polarization parallel to the step planes of PbO and TiO2, respectively. (c) and (d) are charged step models with step planes of PbO and TiO2, respectively. The polarization directions of the domains are marked by the black orientation symbols, and the black and blue solid lines represent the DWs and step planes, respectively. The pink boxes represent periodic supercells. To reveal the step models more clearly, three periods are shown in the direction parallel to the domain walls.
Source publication
The microscopic mechanism of ferroelectric switching is the motion of domain walls, which is actually accomplished by the movement of tiny steps on the domain walls. Using first-principles calculations, the detailed polarization structures and the motion barriers of neutral and charged steps on 180° domain walls of prototypical ferroelectrics PbTiO...
Citations
Conductive domain walls (DWs) in ferroic materials have emerged as promising candidates for applications in nanoelectronics due to their unique properties such as high conductivity and nonvolatility. In this study, we investigate the atomic structure and conductivity of nominally neutral 180° DWs artificially created in an epitaxial thin film of tetragonal PbZr0.1Ti0.9O3. Using piezoresponse force microscopy and scanning transmission electron microscopy, we elucidate the complex structure of these 180° DWs and their coupling with ferroelastic domains, revealing that they exhibit a complex structure due to the strain-mediated interplay with the ferroelastic domains. Our results demonstrate that the 180° DWs conductivity is associated with the emergence of polar discontinuities, including the formation of tail-to-tail charged segments, which has been further confirmed by electron energy loss spectroscopy. Additionally, we investigated the long-term performance of these domain boundaries, demonstrating their unique mobility and structural stability. Our findings provide insights into the atomic-scale mechanisms that turn nominally neutral DWs into highly conductive channels, paving the way for their use in advanced nanoelectronic devices.
