Materials Research Institute, The Pennsylvania State University, University Park, PA, USA.
IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Apr;57(4):792-800. doi: 10.1109/TUFFC.2010.1483.
Ferroelectric polarization switching of high aspect ratio (>80:1) PbZr(0.52)Ti(0.48)O(3) (PZT) microtubes with a wall thickness of ~200 nm was investigated. A charge-based technique was used to assess the dielectric and ferroelectric properties of individual mechanically-unconstrained PZT microtubes with interdigitated electrodes. An enhancement in the degree of ferroelastic (non-180 degrees ) domain wall motion was observed in the tubes relative to films of similar thickness on rigid substrates. The dielectric response of the tubes showed a Rayleigh-like ac field dependence over a wide temperature range; the extent of the extrinsic contribution to the dielectric response dropped as the temperature approached 10K, but remained finite. This work demonstrates a general methodology for directly electrically addressing small, unconstrained ferroelectric devices, extending the range of driving fields and temperatures over which these materials can be probed.
高纵横比(>80:1)的 PbZr(0.52)Ti(0.48)O(3)(PZT)微管的铁电极化翻转,其壁厚约为 200nm,这一现象得到了研究。使用基于电荷的技术来评估具有叉指电极的机械不受约束的单个 PZT 微管的介电和铁电性能。与在刚性基底上的类似厚度的薄膜相比,在这些微管中观察到铁弹性(非 180 度)畴壁运动的增强。在很宽的温度范围内,微管的介电响应表现出类似于瑞利的交流场依赖性;随着温度接近 10K,介电响应的外部贡献程度下降,但仍然存在。这项工作展示了一种直接电寻址小型、无约束铁电器件的通用方法,扩展了这些材料可以被探测的驱动场和温度范围。