Pertsev N A, Petraru A, Kohlstedt H, Waser R, Bdikin I K, Kiselev D, Kholkin A L
A F Ioffe Physico-Technical Institute of the Russian Academy of Sciences, 194021 St Petersburg, Russia.
Nanotechnology. 2008 Sep 17;19(37):375703. doi: 10.1088/0957-4484/19/37/375703. Epub 2008 Aug 1.
Ferroelectric nanodomains were created in BaTiO(3) thin films by applying a voltage to a sharp conducting tip of a scanning force microscope (SFM). The films were epitaxially grown on SrRuO(3)-covered (001)-oriented SrTiO(3) substrates by a high-pressure sputtering. They appeared to be single-crystalline with the (001) crystallographic orientation relative to the substrate. Using the piezoresponse mode of the SFM to detect the out-of-plane film polarization, the domain sizes were measured as a function of the applied writing voltage and the pulse time. It was found that the time dependence of the domain diameter in a 60 nm thick BaTiO(3) film deviates significantly from the logarithmic law observed earlier in Pb(Zr(0.2)Ti(0.8))O(3) (PZT) films. At a given writing time, the domain size increases nonlinearly with increasing applied voltage, in contrast to the linear behavior reported earlier for PZT films and LiNbO(3) single crystals. The dynamics of domain growth is analyzed theoretically taking into account the strong inhomogeneity of the external electric field in the film and the influence of the bottom electrode. It is shown that the observed writing time and voltage dependences of the domain size can be explained by the domain-wall creep in the presence of random-bond disorder.
通过向扫描力显微镜（SFM）的尖锐导电尖端施加电压，在BaTiO(3)薄膜中产生了铁电纳米畴。这些薄膜通过高压溅射在覆盖有SrRuO(3)的（001）取向SrTiO(3)衬底上外延生长。它们相对于衬底似乎是具有（001）晶体取向的单晶。利用SFM的压电响应模式检测薄膜的面外极化，测量了畴尺寸与施加的写入电压和脉冲时间的函数关系。结果发现，60nm厚的BaTiO(3)薄膜中畴直径的时间依赖性与先前在Pb(Zr(0.2)Ti(0.8))O(3)（PZT）薄膜中观察到的对数定律有显著偏差。在给定的写入时间，与先前报道的PZT薄膜和LiNbO(3)单晶的线性行为相反，畴尺寸随施加电压的增加而非线性增加。考虑到薄膜中外部电场的强不均匀性和底部电极的影响，对畴生长动力学进行了理论分析。结果表明，观察到的畴尺寸的写入时间和电压依赖性可以用存在随机键无序时的畴壁蠕变来解释。
