In-Situ and Operando Experiments

This topic is a very broad one since it involves everything that has been covered in W&C and then allows the specimen to change while you image it, record the spectra, and/or measure what changes are taking place. We'll consider what is important when you want to perform an experiment in the TEM. Historically the TEM was a designed around a column with a high(ish) vacuum; the vacuum was not usually high enough to satisfy a UHV expert or poor enough to satisfy a chemist interested in ‘real' reactions. So, we first consider the environment: the specimen can now be in ultra-high vacuum, a poorish vacuum, a controlled gas, or even a liquid. The temperature can be very low (down to liquid-He temperatures), quite low (down to liquid-H2 temperatures), room temperature, or higher temperatures (perhaps as high as 2,000 degrees C).