A MEMS-Based Heating Holder for the Direct Imaging of Simultaneous In-Situ Heating and Biasing Experiments in Scanning/Transmission Electron Microscopes

The introduction of scanning/transmission electron microscopes ( S/TEM) with sub-Angstrom resolution as well as fast and sensitive detection solutions support direct observation of dynamic phenomena in-situ at the atomic scale. Thereby, in-situ specimen holders play a crucial role: accurate control of the applied in-situ stimulus on the nanostructure combined with the overall system stability to assure atomic resolution are paramount for a successful in-situ S/TEM experiment. For those reasons, MEMS-based TEM sample holders are becoming one of the preferred choices, also enabling a high precision in measurements of the in-situ parameter for more reproducible data. A newly developed MEMS-based microheater is presented in combination with the new NanoEx (TM)-i/v TEM sample holder. The concept is built on a four-point probe temperature measurement approach allowing active, accurate local temperature control as well as calorimetry. In this paper, it is shown that it provides high temperature stability up to 1,300 degrees C with a peak temperature of 1,500 degrees C ( also working accurately in gaseous environments), high temperature measurement accuracy (< 4%) and uniform temperature distribution over the heated specimen area (< 1%), enabling not only in-situ S/TEM imaging experiments, but also elemental mapping at elevated temperatures using energy-dispersive X-ray spectroscopy ( EDS). Moreover, it has the unique capability to enable simultaneous heating and biasing experiments. (C) 2016 Wiley Periodicals, Inc.