Hi,

Iron-based alloys should not be a problem. The ferromagnetic behavior of a piece of iron is not enough to interfere with the electron beam. Only two points must be kept under consideration:

- Powder samples of ferromagnetic materials: if the sample is made of or contains powder of magnetically active materials, it can be attracted towards the lenses and interfere in the system.

- Magnets: if the sample is a magnet by itself (not a material that exhibits magnetic behavior, but a magnetic-field generating piece) the force that pushes it towards the lenses may be strong enough to attach to inner pieces of the SEM.

Many ferrous alloys (magnetic and non-magnetic steels, cast irons, stainless steels...) have been observed using SEM with no further consideration.

One of the problem is stigmation must be corrected more frequently. Just travelling on the surface or changing working density may brake down your stigmation setting. The second problem is that some electron microscopes apply magnetic field into the chamber and obtain high resolution. For example, FEI systems have immersion mode for this purpose. In this mode, there must not be anything magnetic inside the chamber. If the specimen is bulk, then it will crash pole piece. If it is powder, the worst scenario will be experienced and particles fly around the chamber or optics in the microscope.

FEI systems have immersion mode for this purpose. In this mode, there must not be anything magnetic inside the chamber. If the specimen is bulk, then it will crash pole piece. If it is powder, the worst scenario will be experienced and particles fly around the chamber or optics in the microscope.