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.

铁磁（FM）|非磁（NM）多层中界面诱导现象的发现使得磁存储器存储密度在过去三十年中迅速增加成为可能。巨磁阻和隧道磁阻现象的发现使得磁矩方向的检测成为可能，并且是磁传感器设计的关键，磁传感器使硬盘驱动器的记录密度增加了 100 倍以上。自旋转移矩（STT）和自旋轨道矩的观察用于操纵磁矩方向，允许固态非易失性磁存储器的新颖设计，该存储器被认为是下一代存储设备。 另一个被深入研究的界面效应是层间交换耦合。由于传统的耦合层仅允许 FM 层的磁矩共线定向，因此这种现象迄今为止尚未得到充分利用。最近，我们发现了新型耦合层 (CL) 材料并获得了专利，该材料可以代替 NM 插入两个铁磁层之间，以精确控制 FM|CL|FM 中 FM 层磁矩的相对方向。这些新的耦合层有可能用于大多数磁性纳米器件，因为磁性纳米器件的最佳设计几乎总是需要至少两个相邻铁磁层之间的非共线对准。 该提案的重点是了解 FM|CL|FM 结构中非共线耦合的起源以及如何将这些结构合并到磁性纳米器件中。重点将放在可从磁矩非共线排列、自旋转移矩磁性随机存取存储器（STT MRAM）和纳米振荡器中获益最多的设备上。与当前最先进的 STT MRAM 设备相比，具有非共线磁矩对准的 STT MRAM 预计将具有更快的写入速度和显着低的功耗。加拿大将从已经和即将产生的重要知识产权中受益，这可能为 HQP 在加拿大开发这些纳米设备创造机会。除了研究层间耦合等静态效应外，我们还将研究磁化动态效应、FM|NM 界面处的自旋泵浦以及随后在 NM 中纯自旋流的传输。特别感兴趣的是 NM = Pt 和 Pd，因为它们在与铁磁薄膜接触时表现出邻近磁化。 Pt 和 Pd 还强烈影响铁磁层的磁静态和动态特性，这可能是有益的，例如增加表面各向异性，也可能是有害的，例如增加磁阻尼。我们将研究通过自旋泵浦和逆自旋霍尔效应增加与 Pt 和 Pd 相邻的铁磁层阻尼的机制。