Speaker
Description
The Photoemission Electron Microscope (PEEM) of the ALBA synchrotron is a versatile surface characterization tool for x-ray nanospectroscopy and spectromicroscopy [1]. It uses photoemitted electrons to form an image of the sample under synchrotron radiation and provides elemental, chemical and magnetic contrast through the tunable x-ray energy and polarization. XPEEM magnetic combines high spatial resolution (down to 20-30 nm) with high surface sensitivity (1-10 nm probing depth) and elemental specificity. Dichroic effects (XMCD, XLD) provide useful contrast mechanisms for ferroic materials (ferromagnets, antiferromagnets, ferroelectrics). The energy filtered electron detection allows for sensitive detection of electric potentials and work function.
There exist many options for in-situ and operando measurements: annealing, evaporation and gas exposure on the sample preparation side. Further measurements parameters are temperature (heating, cooling), electric signals (current or voltage) from DC up to the GHz range [2] and moderate magnetic fields in different geometries (in-plane vector magnet, out-of-plane magnet and in-plane to out-of-plane vector magnet [3]). A new stage for laser excitation of the sample has been installed recently. Time resolved pump-probe experiments synchronized with the synchrotron RF sources can be performed through electrical excitation e.g. of surface acoustic waves or by creating pulsed magnetic fields in striplines. A new direct electron hybrid pixel detector was installed in 2025 as part of the ALBA beamline upgrade program and has significantly improved the detection quality (resolution, signal to noise). It will also provide bunch by bunch time resolution in the future.
User examples will be provided to showcase the possibilities which offers the ALBA-PEEM to the community.
References
[1] L. Aballe et al., J. Synch. Rad. 2015, 22, 745.
[2] M. W. Khaliq et al., Ultramicroscopy 2023, 250, 113757.
[3] M. Foerster et al., Ultramicroscopy, 2016, 171, 163.