Bell Jar HOWTO

STM is a surface sensitive technique, therefore proper storage of samples is a critical step before doing STM. When possible, we measure the samples in the STM right after deposition. If this is not an option, the samples can be stored in the glass bell jar chamber, under vacuum or controlled ambient.

Different gases can be mixed in. Oxides may not be preserved in oxygen poor athmosphere for a very long time, or the first atomic layers will become oxygen depleted. Oxides are very sensitive to contamination by water, therefore they should always be stored away in the bell jar, under dry and clean conditions!

• To vent: slowly open one of the gases valves (N2) and vent till atmospheric pressure.
• To close: pump and flush (with N2) 5 times at least.
• To store: after pumping and flushing, mix in the desired gases and keep at -0.2 to -0.5 bar.

• Remove metal guard ONLY WHEN AT ATMOSPHERIC PRESSURE.
• Use ALWAYS POWDER FREE GLOVES, even to touch the outside of the bell jar (filthy finger prints will be analyzed by forensic institute and evil doers punished.)
• Store samples for STM only. No solvents and smelly stuff! Only dried Ag-paste is allowed!
• KEEP CLEAN.