Rotation of electron beams in the presence of localised, longitudinal magnetic fields

Electron Bessel beams have been generated by inserting an annular aperture in the illumination system of a TEM.

These beams have passed through a localised magnetic field.

As a result a low amount of image rotation (which is expected to be proportional to the longitudinal component of the magnetic field) is observed in the far field.

A measure of this rotation should give access to the magneti field.

The two datasets have been acquired in a FEI Titan3 microscope, operated at 300kV.

The file focal_series.tif contains a series of images acquired varying the magnetic field through the objective lens.

The file line_profile.ser contains a series of images acquired by scanning the beam over a sample with several magnetised nanopillars.

For reference, check the associated publication:
Giulio Guzzinati, Armand Béché, Damien McGrouther and Jo Verbeeck, Prospects for out-of-plane magnetic field measurements through interference of electron vortex modes in the TEM, Journal of Optics 21 124002 (2019)