Graphene nanosensors for scanning Hall microscopy and susceptometry

用于扫描霍尔显微镜和电纳测定法的石墨烯纳米传感器

• 批准号: EP/R007160/1
• 负责人: Simon Bending
• 金额: $ 50.79万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FR007160%2F1
• 关键词: Graphene; nanosensors; scanning; Hall; microscopy

Many of the most important advances in science and technology have only been made possible by parallel developments in instrumentation. For example, the development of microchips, which are now so common in our everyday lives, could not have taken place without the availability of electron microscopy to image cross-sections through prototype devices. Scanning Hall microscopy is a so-called "scanning probe" imaging technique where a tiny sensor is rastered across the surface of a sample to create a map of the magnetic fields. In this case the sensors rely on the Hall effect which arises when the electron flow in a conducting sample is bent by a magnetic field creating a Hall voltage at right angles to the main current direction. At present scanning Hall microscopy is a relatively niche technique that is mainly confined to making measurements of magnetic materials at low temperatures (typically less than -170C). This is due to the fact that although existing Hall effect sensors have high sensitivity at low temperatures, this becomes very much worse at room temperature when other scanning probe imaging methods, for example magnetic force microscopy, are preferred. Recent developments in graphene technology mean that this situation is about to change. Graphene is a single atomic layer of carbon that was first isolated by scientists in Manchester in 2004, leading to the award of the physics Nobel Prize in 2010. It is remarkable for its very high conductivity and mechanical strength, and the electrical carriers in graphene are able to move very much more freely than electrons in copper. Recently scientists have shown that still higher conductivities can be obtained if the graphene is sandwiched between thin layers of an insulator called boron nitride. In this way an improvement in Hall sensor performance of more than a hundred times is possible at room temperature, rivalling the other available magnetic imaging techniques. We also plan to develop new "susceptibility" imaging modes when the Hall probe measures the response of a sample to a small oscillating magnetic field generated by a tiny coil integrated into the sensor. This will allow new types of samples to be studied, and different types of problems can be addressed. Our new sensors target applications in three important technological areas. We will use Hall microscopy to map the nanoscale current distribution in second generation high temperature superconducting tapes that have enormous potential for applications in lossless power transmission and energy storage. Hall susceptometry will be used for the non-invasive detection of defects in "3D printed" materials (for example steel) which are known to play a critical role in structural failure. Finally we will explore how Hall susceptometry can be used for routine process control of the uniformity of the magnetic properties of thin film ferromagnetic materials for applications in data storage.

科学和技术方面的许多最重要的进步都是由于仪器设备的平行发展才得以实现的。例如，现在我们日常生活中如此普遍的微芯片的发展，如果没有电子显微镜通过原型设备对横截面成像的可用性，就不可能发生。扫描霍尔显微镜是一种所谓的“扫描探头”成像技术，它将一个微小的传感器栅格放置在样品的表面上，以创建磁场图。在这种情况下，传感器依赖于霍尔效应，当导电样品中的电子流被磁场弯曲时，产生与主电流方向成直角的霍尔电压。目前，扫描霍尔显微镜是一种相对较小的技术，主要局限于在低温(通常低于-170摄氏度)下对磁性材料进行测量。这是因为，尽管现有的霍尔效应传感器在低温下具有很高的灵敏度，但当其他扫描探针成像方法(如磁力显微镜)被首选时，这种情况在室温下会变得非常糟糕。石墨烯技术的最新发展意味着这种情况即将改变。石墨烯是一种单原子层碳，2004年在曼彻斯特被科学家首次分离出来，导致2010年获得诺贝尔物理学奖。值得注意的是，它具有非常高的导电性和机械强度，而且石墨烯中的电子载体能够比铜中的电子更自由地移动。最近，科学家们已经证明，如果石墨烯夹在一种名为氮化硼的绝缘体的薄层之间，可以获得更高的导电率。通过这种方式，霍尔传感器的性能在室温下有可能提高100倍以上，可以与其他现有的磁成像技术相媲美。我们还计划开发新的“磁化率”成像模式，当霍尔探头测量样品对集成到传感器中的微小线圈产生的小振荡磁场的响应时。这将允许研究新类型的样本，并可以解决不同类型的问题。我们的新型传感器针对三个重要技术领域的应用。我们将使用霍尔显微镜来绘制第二代高温超导带材中的纳米级电流分布，这些带材在无损电力传输和能量存储方面具有巨大的应用潜力。霍尔测电法将用于非侵入性检测“3D打印”材料(例如钢)中的缺陷，这些缺陷被认为在结构失效中起着关键作用。最后，我们将探索如何将霍尔测磁法用于控制薄膜铁磁材料在数据存储中应用的磁性能的均匀性的常规工艺。

项目成果

Superconducting Quantum Interference in Twisted van der Waals Heterostructures.

• DOI: 10.1021/acs.nanolett.1c00152
• 发表时间: 2021-08-25
• 期刊: Nano letters
• 影响因子: 10.8
• 作者: Farrar LS;Nevill A;Lim ZJ;Balakrishnan G;Dale S;Bending SJ
• 通讯作者: Bending SJ

Observing the Suppression of Superconductivity in RbEuFe_{4}As_{4} by Correlated Magnetic Fluctuations.

• DOI: 10.1103/physrevlett.126.157001
• 发表时间: 2020-10
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: D. Collomb;S. Bending;A. Koshelev;M. Smylie;L. Farrar;J. Bao;D. Chung;M. Kanatzidis;W. Kwok;U. Welp

Imaging of Strong Nanoscale Vortex Pinning in GdBaCuO High-Temperature Superconducting Tapes.

• DOI: 10.3390/nano11051082
• 发表时间: 2021-04-22
• 期刊: Nanomaterials (Basel, Switzerland)
• 作者: Collomb D;Zhang M;Yuan W;Bending SJ
• 通讯作者: Bending SJ

High quality hydrogen silsesquioxane encapsulated graphene devices with edge contacts

具有边缘接触的高质量氢倍半硅氧烷封装石墨烯器件

• DOI: 10.1016/j.matlet.2019.126765
• 发表时间: 2019
• 期刊: Materials Letters
• 影响因子: 3
• 作者: Li P

Optimisation of processing conditions during CVD growth of 2D WS2 films from a chloride precursor

• DOI: 10.1007/s10853-021-06708-1
• 发表时间: 2022-01-03
• 期刊: JOURNAL OF MATERIALS SCIENCE
• 影响因子: 4.5
• 作者: Campbell, William R.;Reale, Francesco;Bending, Simon J.
• 通讯作者: Bending, Simon J.