Chemistry for 3D spintronics

自旋电子学在磁传感器领域价值数十亿美元，并在半导体行业（MRAM）中迅速崛起。设备使用磁阻效应（磁化影响电流）和反向自旋转移扭矩（自旋极化电流反转磁化）。自旋电子学需要几种磁性和非磁性材料接触，长度尺度为几纳米。因此，薄膜技术的进步使其解锁，并开发为基于光刻的平面器件。然而，随着传感器和存储器的成熟，在功能或容量方面的限制被发现。需要在所有三个方向上有效地相等地感测场的装置，这难以用平面技术实现。对于存储器来说，对增加面密度的竞争正在将技术推向3D方案，其中大量比特存储在深度中。正是由于这一点，闪存已成为最近的领导者。我们将探索的合成和物理的构建块的三维自旋电子学，基于管和核壳管/线。自上而下的技术在定义这些方面面临局限。相反，我们提出了一个跨学科的财团与两个化学组和自旋电子最终用户。作为一个探索性的项目，我们专注于为两个主要的自旋电子效应和应用类型提供一个构建模块：1。单层（AMR）或核壳三层（GMR或TMR）的磁阻，传感器作为背景。2.在单层或金属/铁核壳双层中的自旋扭矩和自旋霍尔畴壁运动，3D赛道存储器作为潜在的应用。在器件中，管将垂直嵌入介质中，基于光刻的自底向上的孔或通孔中。在第一步中，我们关注从模板中释放出来并在表面上检查的单个对象。合成包括聚合物径迹蚀刻膜和阳极氧化铝模板，电镀（和化学镀）和原子层沉积的金属和绝缘层的核壳。物理测量包括电接触和磁电阻，结合磁显微镜。虽然孔中的电化学已经被用于生产阵列或垂直线几十年，单线的研究，以及自旋电子学，才刚刚出现。只有少数报告存在的磁性管。该项目是探索性的，处于材料科学和自旋电子学的交叉路口。这是一个高风险/高收益、有前途的集成组件颠覆性概念。在短期内，它将为新物理学提供一个游乐场，预计将在磁性与曲率和管道特定拓扑结构的相互作用中发生。此外，另一个影响是促进化学家和自旋电子物理学家之间的联合工作，以解决物理方法面临限制的其他方面。该项目是重新提交的，考虑了评审员的意见。

Spintronics is worth billions in magnetic sensors, and is fast emerging in the semiconductor industry (MRAM). Devices use both effects of magnetoresistance (magnetization influencing electric current) and the reverse, spin-transfer torques (a spin-polarized current to reverse magnetization). Spintronics require several magnetic and non-magnetic materials in contact, with length scales a few nanometers. Thus, it was unlocked by progress in thin film technology, and developed as planar devices based on lithography.However, as sensors and memories are becoming mature, limitations in terms of functions or capacities are identified. Devices for sensing field efficiently equally in all three direction are required, which is difficult to achieve with planar technology. For memories, the competition for increased areal density is driving technology to 3D schemes, in which a large number of bits is stored in the depth. It is thanks to this that flash memory has become a leader recently.We will explore the synthesis and physics of building blocks for a 3D spintronics, based on tubes and core-shell tubes/wires. Top-down techniques face their limits to define these. Instead, we propose an interdisciplinary consortium with two chemistry groups and a spintronic end user. As an exploratory project, we focus on delivering a building block for the two major spintronic effects and type of application: 1. magneto-resistance in single (AMR) or core-shell trilayers (GMR or TMR), with sensors as background. 2. spin-torque and spin-Hall domain-wall motion in single or metal/ferro core-shell bilayers, with the 3D race-track memory as a potential application.In a device the tubes would be embedded vertically in a medium, in bottom-up pores or vias based on lithography. In this first step we focus on single objects freed from their template and inspected at a surface. Synthesis includes polymeric track-etched membranes and anodization of aluminum for templates, electro- (and electroless) plating and atomic layer deposition for both metal and insulating layers of the core-shell. Physical measurements consist of electrical contacting and magneto-resistance, combined with magnetic microscopy.While electrochemistry in pores has been used for decades to produce arrays or vertical wires, investigation on single wires, and spintronics in mind, is only emerging. Only a handful of reports exist on magnetic tubes. The project is exploratory, at the cross-roads of material science and spintronics. It is high risk/high-gain, promising disruptive concepts for integrated components. In the shorter run, it will provide a playground for new physics, predicted to occur with interplay of magnetism with curvature and the specific topology of tubes. Besides, another impact is to foster joint work between chemists and spintronic physicists, to address other aspects where physical methods face limits.The project is a resubmission, taking into account reviewers' comments.