Magnetic induction mapping in the transmission electron microscope using phase contrast techniques such as off-axis electron holography and differential phase contrast imaging often requires the separation of the magnetic contribution to the recorded signal from the electrostatic contribution. When using off-axis electron holography, one of the experimental approaches that can be used to achieve this separation is to evaluate half of the difference between phase shift images that have been recorded before and after turning the sample over. Here, we introduce a cartridge-based sample mounting system, which is based on an existing on-axis tomography specimen holder and can be used to turn a sample over inside the electron microscope, thereby avoiding the need to remove the holder from the microscope to turn the sample over manually. We present three cartridge designs, which are compatible with all pole piece designs and can be used to support conventional 3-mm-diameter sample grids, Si3N4-based membrane chips and needle-shaped specimens. We make use of a wireless inclinometer that has a precision of 0.1° to monitor the sample holder tilt angle independently of the microscope goniometer readout. We also highlight the need to remove geometrical image distortions when aligning pairs of phase shift images that have been recorded before and after turning the sample over. The capabilities of the cartridge-based specimen holder and the turning approach are demonstrated by using off-axis electron holography to record magnetic induction maps of lithographically-patterned soft magnetic Co elements, a focused ion beam milled hard magnetic Nd-Fe-B lamella and an array of four Fe3O4 nanocrystals.

中文翻译：

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基于墨盒的旋转样品架，具有无线倾斜角测量功能，用于透射电子显微镜中的磁感应映射

在透射电子显微镜中使用相衬技术（例如离轴电子全息术和微分相衬成像）进行磁感应映射通常需要将记录信号的磁性贡献与静电贡献分离。当使用离轴电子全息术时，可用于实现这种分离的实验方法之一是评估翻转样品前后记录的相移图像之间差异的一半。在这里，我们介绍了一种基于墨盒的样品安装系统，该系统基于现有的轴上断层扫描样品支架，可用于在电子显微镜内翻转样品，从而避免需要从显微镜中取出支架以手动翻转样品。我们展示了三种墨盒设计，它们与所有极片设计兼容，可用于支持传统的 3 毫米直径样品网格、基于 Si3N4 的膜芯片和针形样品。我们使用精度为 0.1° 的无线测斜仪来独立于显微镜测角仪读数来监测样品架倾斜角。我们还强调需要在对齐翻转样品前后记录的相移图像对时消除几何图像失真。通过使用离轴电子全息术记录光刻图案化软磁 Co 元素的磁感应图，展示了基于墨盒的样品架和转动方法的能力，