Resistive Random Access Memories (ReRAMs) are promising future candidates for nonvolatile memory. The underlying mechanism involves resistive switching in high-k dielectric layers, and changes in resistance due to different mechanisms are caused by the evolution of defective structures triggered by electrical and thermal effects. For the memory purpose of the ReRAM, the electrical field can be used to adjust the resistance of the resistance material for the storage of information. In this study, nonequilibrium molecular dynamics simulations with the charge equilibration method are used to study the electrochemical reactions of ReRAMs. The Cu/TiO₂/Ti heterojunction structures with (100)/(001), (100)/(110), (100)/(111), and (100)/(120) lattice planes as grains are considered to investigate the resistive switching properties based on the electrical, thermal, and structural properties of three models. Dielectric layers with the grain boundary of the bicrystal structure are composed of titanium dioxide nanoparticles. Our results demonstrate that an applied external electric field on grain boundaries is a key issue in resistive switching. Furthermore, the simulation results were verified with the experimental data. Overall, this simulation work provides details of the fundamental mechanism of resistance switching, including variation of the atomic structure and electronic properties, at the atom length scale and picosecond timescale, which suggest a number of useful aspects for the future development and optimization of materials for this ReRAM technology.

中文翻译：

---

TiO2基电阻开关存储器中晶格面取向的影响：一种计算方法

电阻性随机存取存储器（ReRAM）有望成为非易失性存储器的未来候选产品。潜在的机制涉及高k介电层中的电阻切换，并且由于不同机制而导致的电阻变化是由电效应和热效应触发的缺陷结构的演变引起的。出于ReRAM的存储目的，电场可用于调节电阻材料的电阻，以存储信息。在这项研究中，使用电荷平衡方法进行的非平衡分子动力学模拟用于研究ReRAM的电化学反应。铜/钛₂考虑以（100）/（001），（100）/（110），（100）/（111）和（100）/（120）晶格面为晶格的/ Ti异质结结构来研究基于电阻的开关特性关于电，热和结构特性的三种模型。具有双晶结构的晶界的介电层由二氧化钛纳米颗粒组成。我们的结果表明，在晶界上施加外部电场是电阻切换中的关键问题。此外，仿真结果得到了实验数据的验证。总体而言，此仿真工作详细介绍了电阻切换的基本机制，包括原子长度尺度和皮秒时标的原子结构和电子性质的变化，