Ar ion milling system for the selective preparation of TEM specimen

在Philipps-Universität马尔堡材料科学中心，在大学电子显微镜用户设施中操作双像差校正扫描透射电子显微镜（以及其他显微镜）。这种显微镜主要用于新型功能材料领域的研究，如半导体、离子导体和氧化物。在几个协同和单独的项目中，使用了不同的电子显微镜技术，一方面进一步发展电子显微镜技术，另一方面为所研究的功能材料建立结构<=>性质关系。利用高分辨率透射电镜、高分辨率扫描透射电镜、电子能量损失能谱以及四维扫描透射电镜对材料及其界面进行了定量表征。目前制备电子透明样品的方法是用聚焦镓离子束或用宽氩离子束研磨。试样表面的严重损伤是这两种制备技术的结果。这些受损的层使数据的定量评估变得不可能。使用精细聚焦的氩离子束，可以有意地去除受损和离子注入层。这导致样品的电子显微镜调查，这是自由的，从损坏的表面层，这是均匀薄。这不仅有助于提高微观研究的质量，而且使对成分和电场的定量研究成为可能，也可以跨界面进行定量研究。

At the Materials Science Center of Philipps-Universität Marburg a double-aberration corrected scanning transmission electron microscope is operated (amongst other microscopes) in the user facility for electron microscopy of the university. This microscope is used mainly for research in the areas of novel functional materials, like semiconductors, ion conductors, and oxides. In several coordinated as well as individual projects different electron microscopic techniques are used - on the one hand to develop the electron microscopic techniques further and on the other hand to establish a structure <=> property relationship for the functional materials investigated. High resolution transmission electron microscopy, high resolution scanning transmission electron microscopy, electron energy loss spectroscopy are used as well as four-dimensional scanning transmission electron microscopy to characterize the materials and their interfaces quantitatively. Electron transparent samples are currently prepared either by milling using a focused Gallium ion beam or by milling with a broad Argon ion beam. Severe damage of the specimen surfaces is a result of both preparation techniques. These damaged layers make quantitative evaluation of data impossible. The damaged and ion implanted layers can be intentionally removed with the proposed ion mill using a finely focused Argon ion beam. This results in specimens for electron microscopic investigations, which are free from damaged surface layers and which are homogeneously thin. This not only helps to improve the quality of microscopic investigations, but also makes quantitative studies on composition and on electric fields possible, also across interfaces.