MagTEM2 - the next generation microscope for imaging functional materials

将材料的原子级结构与其功能相关联是我们理解物理和化学世界的核心，因此对大多数技术发展也是如此。扫描透射电子显微镜(STEM)现在物理科学中的高分辨率材料表征中占据主导地位，常规地揭示否则难以辨别的结构细节。它擅长分析非周期结构，包括缺陷、不均匀和界面，这些缺陷和界面低于其他显微镜的分辨率，无法用衍射进行研究。这些结构很重要，因为它们往往决定着一种材料的性质，无论是好是坏。原子尺度的分辨率也支撑着设备的发展，现在这些器件可能只包含几十个原子的尺寸特征，通常是为了利用只能在纳米尺度上控制的量子效应。令人震惊的是，许多材料仍然无法获得原子分辨率的STEM。一个例子是，用来聚焦STEM仪器的磁场干扰了磁性样品，因此无法研究它们的本征行为。我们建议利用我们的专业知识来解决这个问题。首先，我们将利用改进的电子透镜设计，将无场成像分辨率提高三倍。我们将能够在原子尺度上可视化样品本身的电磁场，促进对磁、量子、微电子和等离子体技术的新颖研究，以及具有纳米磁性的地质和化学样品。对磁性结构的敏感性的提高将使具有挑战性的样品的分析成为可能，例如合成反铁磁体和低磁矩材料，这些都具有技术重要性。我们还将通过集成最新的用于成像和光谱分析的无噪声电子探测器来提高时间分辨率和灵敏度，为高速、高灵敏度分析提供增强的能力，特别是对精致的光束敏感材料的分析。我们在这两个领域都处于发展的前沿，并处于非常有利的地位，可以发展成为公认的英国研究实力。

Correlating a material's atomic-scale structure to its functionality is central to our understanding of the physical and chemical world, and hence to most technological development. Scanning transmission electron microscopy (STEM) now dominates high resolution materials characterisation in the physical sciences, routinely revealing structural details that are otherwise indiscernible. It excels in the analysis of aperiodic structures including defects, inhomogeneities and interfaces that are below the resolution of other microscopies and cannot be studied using diffraction. These structures are important because they often dominate a material's properties, for better or worse. Atomic-scale resolution also underpins the development of devices, which may now contain features of only a few tens of atoms in dimension, often to harness quantum effects that can only be controlled on the nanoscale.Frustratingly, many materials remain inaccessible to atomic resolution STEM. One example is that the magnetic fields used to focus a STEM instrument interfere with magnetic samples, so that their intrinsic behaviour cannot be studied. We propose to capitalise on our expertise to address this problem. First, we will exploit improved electron lens designs to provide a three-fold improvement in 'field-free' imaging resolution. We will be able to visualise a sample's own electromagnetic fields on the atomic scale, facilitating novel studies of magnetic, quantum, microelectronic and plasmonic technologies alongside geological and chemical samples with nano-magnetic properties. An improved sensitivity to magnetic structure will enable the analysis of challenging samples such as synthetic antiferromagnets and low moment materials, which are of technological importance. We will also enhance time resolution and sensitivity by integrating the latest noise-free electron detectors for imaging and spectroscopy, providing enhanced capabilities for high-speed, high sensitivity analysis, particularly of delicate, beam-sensitive materials. We have been at the forefront of development in both of these areas and are exceptionally well-placed to grow an acknowledged UK research strength.