Kim D J, Connell J G, Seo S S A, Gruverman A
Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA. Center for Correlated Electron Systems, Institute for Basic Science, Seoul 151-742, Korea. Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea.
Nanotechnology. 2016 Apr 15;27(15):155705. doi: 10.1088/0957-4484/27/15/155705. Epub 2016 Mar 2.
Although enhanced conductivity of ferroelectric domain boundaries has been found in BiFeO3 and Pb(Zr,Ti)O3 films as well as hexagonal rare-earth manganite single crystals, the mechanism of the domain wall conductivity is still under debate. Using conductive atomic force microscopy, we observe enhanced conductance at the electrically-neutral domain walls in semiconducting hexagonal ferroelectric TbMnO3 thin films where the structure and polarization direction are strongly constrained along the c-axis. This result indicates that domain wall conductivity in ferroelectric rare-earth manganites is not limited to charged domain walls. We show that the observed conductivity in the TbMnO3 films is governed by a single conduction mechanism, namely, the back-to-back Schottky diodes tuned by the segregation of defects.
尽管在BiFeO3和Pb(Zr,Ti)O3薄膜以及六方稀土锰氧化物单晶中已发现铁电畴界的导电性增强，但畴壁导电的机制仍存在争议。利用导电原子力显微镜，我们在半导体六方铁电TbMnO3薄膜的电中性畴壁处观察到增强的电导，该薄膜的结构和极化方向沿c轴受到强烈约束。这一结果表明，铁电稀土锰氧化物中的畴壁导电不限于带电畴壁。我们表明，在TbMnO3薄膜中观察到的导电性由单一传导机制控制，即由缺陷偏析调节的背对背肖特基二极管。
