发表机构
The Pennsylvania State University; Carnegie Mellon University（宾夕法尼亚州立大学; 卡内基梅隆大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过ReaxFF分子动力学模拟，揭示了ZnO/Zn1-xMgxO异质结构中层拓扑和界面机械约束对铁电切换的关键作用，发现ZnO居中结构可在更低电场下切换，为设计纤锌矿铁电异质结构提供了新变量。
AI 中文摘要
异质结构中的铁电切换将组分、层拓扑、温度和界面边界条件耦合在一起。ReaxFF分子动力学在ZnO/Zn1-xMgxO/ZnO和Zn1-xMgxO/ZnO/Zn1-xMgxO堆叠中隔离了这些变量。在原始、初始单域模型中，与可切换的Zn1-xMgxO的耦合将反转ZnO所需的外加电场降低了最多五倍。温度通常降低矫顽场，而Mg浓度产生非单调响应。在ZnO和Zn1-xMgxO（ZMO）比例相等时，所有四个考察温度下，ZnO位于中心的结构比ZMO位于中心的结构在更低电场下切换，展示了拓扑依赖的响应。层分辨轨迹揭示了拓扑依赖的切换序列，伴随异质界面附近法向应力的方向依赖重新分布，与应力辅助的协同路径一致。含MgO的限制结构表现出顺序多级切换或低极性俘获，取决于厚度和温度。固定电荷原子模拟通过解析在共同外加电场下的结构、能量和局部应力演化，补充了先前的连续介质描述。TEM和STEM-EDS观察为模拟架构提供了实验结构背景。总之，这些结果确立了层拓扑和界面机械约束作为纤锌矿铁电异质结构的设计变量。
英文摘要
Ferroelectric switching in heterostructures couples composition, layer topology, temperature, and interfacial boundary conditions. ReaxFF molecular dynamics isolates these variables in ZnO/ Zn1- xMgxO/ZnO and Zn1-xMgxO/ZnO/ Zn1-xMgxO stacks. Within pristine, initially single-domain models, coupling to switchable Zn1-xMgxO reduces the applied field required to reverse ZnO by up to fivefold. Temperature generally lowers the coercive field, whereas Mg concentration produces a nonmonotonic response. At equal ZnO and Zn1-xMgxO (ZMO) proportions, structures with ZnO at the center switch at lower fields than those with ZMO at the center at all four temperatures examined, demonstrating a topology-dependent response. Layer-resolved trajectories reveal topology-dependent switching sequences with direction-dependent redistribution of normal stress near the heterointerfaces, consistent with a stress-assisted cooperative pathway. Limiting MgO-containing structures exhibit sequential multilevel switching or low-polarity trapping, depending on thickness and temperature. Fixed-charge atomistic simulations complement previous continuum descriptions by resolving structural, energetic, and local stress evolution under a common applied field. TEM and STEM-EDS observations provide experimental structural context for the modeled architectures. Together, the results establish layer topology and interfacial mechanical confinement as design variables for wurtzite ferroelectric heterostructures.
