A three-dimensional multiscale peridynamics model for Ferroelectric/Multiferroic Tunnel Junctions

铁电/多铁隧道结的三维多尺度近场动力学模型

基本信息

批准号：
286791468
负责人：
Professor Dr.-Ing. Timon Rabczuk, Ph.D.
金额：
--
依托单位：
Institut für Strukturmechanik (ISM)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/286791468?language=en
关键词：
three dimensional multiscale peridynamics model

项目摘要

In this project, a three-dimensional multiscale peridynamics (PD) model for fracture in ferroelectric/multiferroic tunnel junctions is proposed. A ferroelectric tunnel junction (FTJ) is a ferroelectric sandwich layer used as a barrier material between electrodes for tunneling of electrones. By using ferromagnetic electrodes the functionality of FTJs can be extended to create multiferroic tunnel junctions (MTJs). FTJs/MTJs have been widely used in electronic devices such as ferroelectric memories, microsystems, tunable microwaves, binary data storage, ferroelectric random access memories (FRAMs), among others. Fracture in FTJ/MTJs can influence their reliability. For instance, it might lead to the reduction of the electric field seen by the ferroelectric thin-film. One popular fracture mechanism in ferroelectric thin-films is caused by the polarization switching and results in a systematic loss of the remanent switchable polarization as a function of the number of bipolar switching cycles. A molecular dynamics (MD) model for FTJ/MTJs should be devised at the fine scale while a state-based thermomechanical-electromagnetic PD continuum model needs to be developed at the coarse-scale. The transfer of length scales is accomplished through higher order gradient (HOG) models of the PD and the MD models so that they show the same dynamic dispersion. The advantage of the PD model over existing models such as XFEM is its ease in handling discontinuities as they are a natural outcome of the analysis. No representation of the crack topology is needed. Moreover, due to the non-local character of the PD model, it can be coupled to the MD model in a more natural way. The approach will be verified and validated by comparison to available experimental data and used in order to answer some urgent questions related to the fracture behavior in FTJ/MTJs.

在这个项目中，提出了铁电/多表情隧道连接中的骨折的三维多尺度perideganics（PD）模型。铁电隧道连接处（FTJ）是一种铁电夹层，用作电子隧穿的电极之间的屏障材料。通过使用铁磁电极，可以扩展FTJ的功能以创建多效性隧道连接（MTJ）。 FTJ/MTJ已被广泛用于电子设备，例如铁电内存，微型系统，可调微波，二进制数据存储，铁电随机访问记忆（FRAM）等。 FTJ/MTJ中的断裂会影响其可靠性。例如，这可能导致铁电薄膜看到的电场减少。铁电薄膜中一种流行的断裂机制是由极化切换引起的，并导致可系统损失可转移的可切换极化，这是双极切换循环数量的函数。 FTJ/MTJS的分子动力学（MD）模型应在精细规模上设计，而在粗尺度上需要开发基于州的热机械 - 电磁PD连续模型。长度尺度的传递是通过PD和MD模型的高阶梯度（HOG）模型完成的，以便它们显示相同的动态分散。 PD模型比XFEM等现有模型的优点在于处理不连续性，因为它们是分析的自然结果。不需要裂纹拓扑的代表。此外，由于PD模型的非本地特征，它可以以更自然的方式耦合到MD模型。该方法将通过与可用的实验数据进行比较来验证和验证，并用于回答与FTJ/MTJ中断裂行为有关的一些紧急问题。