Atomic-Scale Characterization of 180° Conductive Domain Walls in PbZr_0.1Ti_0.9O₃

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 PbZr_0.1Ti_0.9O₃. 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.