Spatially confined electronic materials for resistive switching devices

我以前和现在的研究主要集中在磁性氧化物(锰氧化物)薄膜和微桥的合成以及对它们的电子/材料性质的研究。这些研究导致在这些材料中发现了不寻常的材料特性(如各向异性磁阻AMR)。大的AMR可以用在磁性开关设备中。我希望AMR在微桥领域达到巨大的规模。我计划增加AMR的尺寸，包括使用电子束对锰氧化物薄膜的纳米桥进行修饰，以及使这些桥承受(在压电器件中)的应力。这些程序可能会改变这些材料的电桥的性质(电子相分离)。*我计划利用我在锰氧化物材料和技术方面的经验来研究导致介质氧化物薄膜中不寻常的传输特性(电阻开关(RS))的机制。通常，介质中的电阻变化是非易失性的，也就是说，在移除施加的电场之后，所产生的电阻可以保持很长时间。这表明电场诱导RS可用于下一代随机存取存储器件。我计划首先研究典型的多层介质系统。这些氧化物和锰氧化物之间有许多“相似之处”。缺陷的迁移及其形成对两种材料中的剪应力都非常敏感。此外，介电氧化物中的电输运似乎是由丝状渗流电导引起的，这与在锰氧化物中观察到的情况类似。我想了解这些细丝的形成以及它们对介质氧化物中RS的影响。我想了解这些介质中的细丝，它形成的激活能，以及它的结构性质。我想回答一个重要的问题：这些细丝是由扩展缺陷形成的，还是氧缺陷的电迁移形成的？我的研究计划是研究使用压电(PMNT基应力产生)器件和离子液体基能产生大电场的器件的不同类型的介质氧化物多层系统的电/结构材料性能的变化。使用这种技术，我想要区分由于延长的缺陷和那些由于形成丝状RS中的氧缺陷的电迁移而产生的影响。扩展缺陷的数量强烈地依赖于剪应力。另一方面，缺陷的电迁移强烈依赖于电场。因此，外加的应力和电场可以帮助我将介电系统器件“调整”到能够产生大RS的条件。*这项研究的目标可以让我生产用于RS交换目的的新型设备，以及更详细地了解RS的机制。*

My previous and current research has been focused on synthesis of thin films and micro-bridges of magnetic oxides (manganites) and studies of their electronic/material properties. These studies led to discovery of unusual material properties (such as, anisotropic magnetoresistance AMR) in these materials. Large AMR can be used in magnetic switching devices. I want AMR to reach colossal size in micro-bridges. My plans to increase the size of AMR include modification of nano-bridges of manganite films using an electron beam, as well as subjecting these bridges to stress (in piezoelectric devices). These procedures could change properties (electronic phase separation) in bridges of these materials.******I am planning to use my experience with manganite materials and techniques to investigate the mechanisms responsible for unusual transport properties (resistive switching (RS)) in dielectric oxide films. Typically, the change in resistance in the dielectrics is "non-volatile" i.e., the resulting resistance can be maintained for a long time after the removal of the applied electric field. It was suggested that electric field-induced RS could be used for the next-generation random-access memory devices. I am planning first to investigate prototypical multilayer dielectric systems. There are many “parallels” between these oxides and manganites. Migration of defects and its formation are very sensitive to the shear stress in both materials. Also, the electrical transport in the dielectric oxides appears to be caused by the filamentary percolation conductivity, which is like that observed in manganites. I want to understand formation of these filaments as well as their influence on RS in dielectric oxides.******I want to understand filaments in these dielectrics, the activation energy of its formation, and its structural nature. I want to answer important question; Are these filaments formed by extended defects or electro-migration of oxygen defects? My research plan is to investigate changes in the electric/structural material properties of the different types of dielectric oxide multilayer systems using piezoelectric (PMNT-based stress producing) devices, and ionic-liquid based devices capable of producing large electric field. Using this techniques, I want to separate effects due to the extended defects from those due to the electro-migration of oxygen defects in the formation of filamentary RS. The number of extended defects depends strongly on the shear stress. On the other hand, the electro-migration of defects depends strongly on the electric field. Therefore, the applied stress and electric field could help me to “tune” the dielectric system devices to conditions capable of producing large RS. ******The goal of this research could allow me to produce new type of devices for RS switching purposes, as well as to understand in more detail the mechanism of RS.********