Charge transport across the interfaces in complex oxides attracts a lot of attention because it allows creating novel functionalities useful for device applications. It has been observed that movable domain walls in epitaxial BiFeO₃ films possess enhanced conductivity that can be used for reading out in ferroelectric-based memories. In this work, the relation between the polarization, strain and conductivity in sol-gel BiFeO₃ films with special emphasis on grain boundaries as natural interfaces in polycrystalline ferroelectrics is investigated. The interaction between polarization and grain boundaries occuring at elevated temperatures during or after material sintering stage leads to the formation of branched network of highly conductive grain boundaries with the electrical conductivity about two orders higher than in the bulk. At room temperature, these conductive traces stabilized by the defects remain and do not change upon polarization switching. These collective states provide further insight into the physics of complex oxide ferroelectrics and may strongly affect their practical applications, because reveal an additional mechanism of the leakage current in such systems.

跨复杂氧化物氧化物界面的电荷传输引起了很多关注，因为它允许创建对器件应用有用的新颖功能。已经观察到，外延BiFeO ₃膜中的可移动畴壁具有增强的导电性，可用于基于铁电的存储器中的读出。在这项工作中，溶胶-凝胶BiFeO _3中的极化，应变和电导率之间的关系研究了特别强调晶界作为多晶铁电体自然界面的薄膜。在材料烧结阶段期间或之后，在高温下发生的极化和晶界之间的相互作用导致形成高导电晶界的分支网络，其电导率比整体中高约两个数量级。在室温下，这些由缺陷稳定的导电迹线会保留下来，并且在极化切换时不会改变。这些集体状态提供了对复杂氧化物铁电体物理的进一步了解，并可能强烈影响其实际应用，因为揭示了此类系统中漏电流的其他机制。