Tyunina M
IEEE Trans Ultrason Ferroelectr Freq Control. 2021 Feb;68(2):296-302. doi: 10.1109/TUFFC.2020.2978901. Epub 2021 Jan 26.
Mobile oxygen vacancies are increasingly widely believed to be responsible for electrical conductivity in perovskite oxide ferroelectrics. Here, this hypothesis is debated. The small-signal conductivity is investigated in oxygen-deficient films of barium titanate, where oxygen vacancies are epitaxially clamped and immobile. The observed behavior of conductivity as a function of temperature and frequency evidences pure electronic processes. Importantly, it is shown that these processes mimic motion of oxygen vacancies, which are immobile. It is also demonstrated that under the applied dc electric field, the electronic processes lead to such effects as coloration and degradation, which before were plausibly ascribed to migration of oxygen vacancies. Finally, it is concluded that the hypothesis of mobile oxygen vacancies is misleading.
越来越多的人广泛认为，移动氧空位是钙钛矿氧化物铁电体中电导率的原因。在此，对这一假设进行了辩论。在钛酸钡的缺氧薄膜中研究了小信号电导率，其中氧空位被外延固定且不移动。观察到的电导率随温度和频率变化的行为证明了纯粹的电子过程。重要的是，结果表明这些过程模拟了不移动的氧空位的运动。还证明了在施加的直流电场下，电子过程会导致诸如着色和降解等效应，而这些效应之前被合理地归因于氧空位的迁移。最后得出结论，移动氧空位的假设具有误导性。
