Restrictions on evaporants and gases

LEEM is well-known for its capability to study growth processes in-situ. This means that, as you deposit, you can observe the growth in video rate. In the experimental chamber, six ports can host e-beam evaporators (Omicron EMF 3, Elmitec) or custom-made basket evaporators.

What can and cannot be evaporated

• You are requested to contact the beamline coordinators in order to discuss all issues about evaporators and evaporants. We allow the evaporation of the following elements: Au, Ag, Co, Cu, Fe, Ge, Ni, Mn, Pb, Pd, Pt, Rh, Si. Notice that the evaporation of volatile elements such as Ga, As, Sb, organo-metallics and polymers is not permitted as it results in the contamination of the objective and sample cartridge. Organic molecules may be evaporated only in special cases, if the molecules can be  eliminated by baking at 140°C and highly collimated beams are used for deposition on the sample. If you have further questions on these issues, please get in touch with the beamline contacts well in advance prior to submission.

• Please understand that the maintenance of the instrument is not easy and requires long time. De-contamination is a lengthy process, which require mechanical cleaning of the objective lens and sample cartridge.

Sending us your evaporators

The users are invited to send us their own evaporators for experiments, after ensuring they can be mounted on the microscope (instructions for sending us goods can be found in the contacts section). The evaporators must be sent to the contact person at Elettra, arranging the delivery so that they can be mounted before the start of the run. Omicron EMF3 e-beam evaporators are provided only under special circumstances and we do not accept responsibility for failure of the evaporators.

Experiment with gases

The main chamber of the SPELEEM is served by a gas line with two precision leak valves. A magnetic bearing turbo pump allow using the main chamber as a gas flow reactor, up to a maximum pressure of 1·10^-6 mbar when the beamline is open. This figure can be increased to 1·10^-5 mbar is the microscope is isolated from the beamline (LEEM mode). When working with gases, one has to deal with several hazards. Therfore you must discuss safety issues with the beamline coordinator. We allow the use of CO, O₂, H₂ and N₂ and NO.