Scanning transmission electron microscopy (STEM) is a powerful technique for the study of atomic structure and spectroscopic fingerprints of materials down to the level of individual atoms. However, in typical instruments the samples need to be inserted through air, which makes the study of air sensitive samples difficult with this method. In this contribution, I present some of the first results from the Vienna setup built around a Nion UltraSTEM100 that allows the transfer of samples between external systems and the microscope in an Ar atmosphere, as well as between different experimental setups within the ultra-high vacuum system connected to the microscope.
The main focus of the presentation will be on physical manipulation of 2D materials in the microscope through the knock-on mechanism using the Ångström-sized electron probe and chemical manipulation of graphene through controlled low-pressure atmospheres around the sample, but also examples of other studies from the same system will be shown. Theoretical aspects of the manipulation will also be addressed in the context of extending the method to materials beyond graphene.