Multilevel hysteresis loop engineered with ferroelectric nano-metamaterials
Multilevel hysteresis loop engineered with ferroelectric nano-metamaterials
复制标题
DOI：
10.1016/j.actamat.2016.11.065
复制
发表时间：
2017-02-15
期刊：
影响因子：
9.4
通讯作者：
Kitamura, Takayuki
中科院分区：
文献类型：
--
作者：
Van Lich, Le;Shimada, Takahiro;Kitamura, Takayuki
铁电和多铁性材料中的极化开关提供了设计广泛的多功能器件的手段。迄今为止，这样的应用通常已经利用铁电极化切换，其中极化矢量可以在与外部电场平行或反平行之间交替，即，两个州然而，开关的方向和长程序参量之间的耦合限制了定义明确的偏振态，阻碍了偏振开关的使用和新应用的进展。使用铁电纳米超材料的概念，我们在这里证明，连续的极化切换通过多个定义良好的稳定状态与远程序参数从切换方向解耦可以实现，因此，可控和多级磁滞回线下得到一个单向电场。基于铁电纳米超材料的概念，设计了一种纳米多孔铁电结构，调整了稳定态的平衡极化结构。然后控制均匀电场的取向以实现期望的极化切换行为，并因此实现可以通过所有稳定极化状态的磁滞回线水平。此外，建立了开关的纳米结构-状态-水平的一般规则，从该规则可以设计和实现高水平的磁滞回线。本研究为基于多级铁电开关的新型器件，如多级数据存储存储器、多逻辑门和多级控制机电器件等提供了基础。(C)2016 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
Polarization switching in ferroelectric and multiferroic materials provides a means of designing a broad range of multifunctional devices. To date, such applications have typically exploited 180 ferroelectric polarization switching, where the polarization vector can be alternated between parallel or anti-parallel to the external electric field, i.e., bi-states. However, the coupling between the direction of switching and the long-range order parameter puts a limit on the well-defined polarization state, hindering the use of polarization switching and the advancement of novel applications. Using the ferroelectric nano-metamaterial concept, we demonstrate here that successive polarization switching through multiple well-defined stable states with a long-range order parameter decoupled from the direction of switching can be achieved, and consequently, controllable and multilevel hysteresis loops are obtained under a unidirectional electric field. The equilibrium polarization configuration of stable states are tailored by designing a nanoporous ferroelectric structure based on the ferroelectric nano-metamaterial concept. The orientation of the homogeneous electric field is then controlled to achieve the desired polarization switching behavior and hence the hysteresis loop level, which can pass through all stable polarization states. In addition, a general rule for the nanostructure-state-level of switching is established, from which a high level of hysteresis loop can be designed and achieved. The present study provides a foundation for novel devices based on multilevel ferroelectric switching, such as multilevel data storage memory, multi-logic gates, and electromechanical devices with multilevel control. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.