Creating and understanding magnetotransport properties in manganite based devices

一类重要的器件，包括用于磁传感和记录应用的器件，之所以起作用，是因为它们的电阻随磁场的强度和方向发生显著变化。我提出的研究旨在理解和操纵一套独特的基于锰氧化物(锰氧化物)薄膜的超材料的这些特性。在这些系统中，我们计划控制自然存在于其中的微小磁性不均匀的形状、大小和接近程度。这样的操作将使我们能够产生创纪录的价值和/或前所未有的电气性能，这对技术来说很重要。产生这种新颖行为的方法包括调整作用在器件上的应变，并使用电子束将纳米尺度的图案写入磁性不均匀。电学性质包括各向异性磁阻(AMR)，即取决于磁场方向的电阻变化，以及隧道磁阻(TMR)，这一现象通常与量子力学性质有关，其中电子显然可以滑过通常会阻碍其运动的“势垒”。因此，我们研究的总体目标有两个：(I)提高对这些有趣设备背后有趣的科学问题的理解，以及(Ii)使研究人员能够潜在地利用其高度敏感的可调性来进行新的应用。

An important class of devices, including those used in magnetic sensing and recording applications, function because their resistances change significantly with the strength and direction of the magnetic field. My proposed research is aimed at understanding and manipulating these properties in a unique set of metamaterials based on manganese oxide (manganite) thin films. In these systems, we plan to control the shape, size and proximity of the small magnetic inhomogeneities that naturally exist within them. Such manipulation will enable us to produce record breaking values and/or never-seen-before electrical properties that are important for techonology. Methods for producing such novel behaviour include adjusting the strain acting on the device and using electron beams to write nanometer scale patterns into the magnetic inhomogeneities. The electrical properties include the anisotropic magnetoresistance (AMR), i.e. the change in the resistance that depends on the orientation of the magnetic field, and the tunneling magnetoresistance (TMR), a phenomenon that is commonly associated with a quantum mechanical property where electrons can apparently slip through a “barrier” which would normally impede its motion. Hence, the general goals of our investigations are twofold: (i) improve the understanding of the interesting scientific issues behind these interesting devices, and (ii) enable researchers to potentially utilize their highly sensitive tunability for new applications.*****