Centre Energie, Materiaux et Telecommunications, Institut National de la Recherche Scientifique, Varennes, QC, Canada.
IEEE Trans Ultrason Ferroelectr Freq Control. 2012 Sep;59(9):1903-11. doi: 10.1109/TUFFC.2012.2405.
We report the piezoelectric and ferroelectric properties of individual one-dimensional objects made of Bi(4)Ti(3)O(12) (BiT). The nanorods and nanowires investigated in this study were fabricated by a two-step process: 1) preparation of reactive templates using hydrothermal-like synthesis and colloidal chemistry and 2) transformation of the reactive templates in Bi(4)Ti(3)O(12) by solid-state reaction, overcoming the morphological instability problem of 1-D templates. Using piezoresponse force microscopy (PFM) with both out-of-plane and in-plane detection capability, we show that both types of objects exhibit strong piezoelectric activity and good switching ferroelectric behavior. Analysis of the PFM hysteresis loops obtained revealed that the coercive voltage of the in-plane PFM signal can be either equal to or different from that of the out-of-plane response. We associate these situations with two types of polarization switching mechanisms: direct 180° switching, and via rotation of polarization, resulting from the independent switching of the components along the a- and ccrystallographic axes. In a few instances, we observe a negative piezoelectric coefficient, which we explain by the specific shape of the piezoelectric surface of Bi(4)Ti(3)O(12).
我们报告了由 Bi(4)Ti(3)O(12)（BiT）制成的一维个体物体的压电和铁电性能。本研究中研究的纳米棒和纳米线是通过两步工艺制备的：1）使用水热类似合成和胶体化学制备反应模板，2）通过固态反应将反应模板转化为 Bi(4)Ti(3)O(12)，克服了 1-D 模板的形态不稳定性问题。使用具有面外和面内检测能力的压电力显微镜（PFM），我们表明这两种类型的物体都表现出强烈的压电活性和良好的开关铁电行为。获得的 PFM 滞后环的分析表明，面内 PFM 信号的矫顽电压可以等于或不同于面外响应的矫顽电压。我们将这些情况与两种类型的极化反转机制相关联：直接 180°反转，以及由于沿 a 和 ccrystallographic 轴独立反转而导致的极化旋转。在少数情况下，我们观察到负的压电系数，我们通过 Bi(4)Ti(3)O(12 的压电表面的特定形状来解释这种现象。
