Interface induced magnetic properties of thin films

薄膜的界面感应磁特性

• 批准号: RGPIN-2019-07203
• 负责人: Girt, Erol
• 金额: $ 2.99万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762468
• 关键词: Interface; induced; magnetic; properties; thin

The rapid increase in magnetic memory storage density over the last three decades has been made possible by the discovery of interface-induced phenomena in ferromagnetic (FM)|non-magnetic (NM) multilayers. The discovery of giant magnetoresistance and tunnel magnetoresistance phenomena enabled the detection of magnetic moment direction and are key for the design of magnetic sensors that are responsible for >100 times increase in the recording density of hard drives. The observation of spin transfer torque (STT) and spin orbit torque, utilized to manipulate the magnetic moment direction, allows for a novel design of solid state non-volatile magnetic memories, which are identified as the next generation in memory devices. Another interface effect that has been intensively studied is the interlayer exchange coupling. This phenomenon has not been used to its full potential until now, since traditional coupling layers only allow for collinear orientation of magnetic moments of FM layers. Recently, we discovered and patented new coupling layer (CL) materials, which can be inserted instead of NM, between two ferromagnetic layers to precisely control the relative orientation of the magnetic moments of FM layers in FM|CL|FM. These new coupling layers have the potential to be used in the majority of magnetic nanodevices since the optimal design of magnetic nanodevices almost always requires non-collinear alignment between at least two neighboring ferromagnetic layers. This proposal focuses on understanding the origin of non-collinear coupling in FM|CL|FM structures and how to incorporate these structures into magnetic nanodevices. The emphasis will be on devices, which could benefit most from non-collinear alignment of magnetic moments, spin transfer torque magnetic random-access memories (STT MRAM), and nano-oscillators. STT MRAM with non-collinear alignment of magnetic moments are expected to have much faster write speeds and significantly low power consumption than the current state-of-the-art STT MRAM devices. Canada will benefit from significant intellectual property that has already been and will be generated, which could create an opportunity for HQP to develop these nanodevices in Canada. In addition to studying static effects, such as interlayer coupling, we will also study magnetization dynamic effects, spin pumping at FM|NM interfaces, and the subsequent transport of pure spin current in NM. Of specific interest are NM = Pt and Pd since they exhibit proximity magnetization when interfaced with ferromagnetic films. Pt and Pd also strongly affect magnetic static and dynamic properties of ferromagnetic layers, which can be beneficial like increase of surface anisotropy or detrimental like increase of magnetic damping. We will study the mechanisms responsible for increase of damping of ferromagnetic layers adjacent to Pt and Pd by means of spin pumping and inverse spin Hall effect.

在过去三十年中，通过发现界面诱导的现象（FM）|非磁性（NM）多层的现象，磁性记忆存储密度的迅速增加已成为可能。发现巨型磁倍率和隧道磁磁性现象的发现使磁矩方向的检测能够检测，并且是设计磁性传感器的关键，这些磁性传感器的记录密度在硬盘驱动器的记录密度上增加了100倍。用于操纵磁矩方向的自旋传递扭矩（STT）和自旋轨道扭矩的观察，可以对固态非挥发性磁性记忆进行新颖的设计，这些磁性磁性记忆被确定为记忆设备中的下一代。 深入研究的另一个接口效应是层间交换耦合。直到现在，这种现象尚未充分发挥其全部潜力，因为传统耦合层仅允许FM层的磁性矩实现。最近，我们发现并获得了专利的新耦合层（CL）材料，可以插入两个铁磁层之间，以精确控制FM | Cl | FM中FM层的磁矩的相对方向。这些新的耦合层有可能在大多数磁性纳米台词中使用，因为磁性纳米版的最佳设计几乎总是需要至少两个相邻的铁磁层之间的非共线。 该提案的重点是理解FM | Cl | FM结构中非共线耦合的起源，以及如何将这些结构纳入磁性纳米台词。重点将放在设备上，这些设备可能会受益于磁矩的非共线，自旋转移磁性随机访问记忆（STT MRAM）和纳米振荡器。与当前最新的STT MRAM设备相比，具有非共线对齐的STT MRAM预计将具有更快的写入速度，并且功耗明显更低。加拿大将受益于已经并且将会产生的重要知识产权，这可能为HQP创造机会在加拿大开发这些纳米杂志。除了研究静态效应（例如层间耦合）外，我们还将研究磁化动态效应，FM | NM接口处的自旋泵浦以及随后在NM中纯自旋电流的运输。特定感兴趣的是NM = PT和PD，因为当它们与铁磁膜连接时，它们表现出接近磁化。 PT和PD还强烈影响铁磁层的磁性静态和动态特性，这可能是有益的，例如表面各向异性的增加或有害的磁阻尼的增加。我们将研究负责通过自旋泵送和旋转霍尔效应邻近PT和PD的铁磁层阻尼的机制。