Hard X-Ray Photoelectron Spectroscopy of Deeply Buried Magnetic Layers

This work focuses on the investigation of multilayer structures, employed in spintronics devices, by a number of techniques based on hard x-ray photoelectron spectroscopy (HAXPES). The application of hard x-rays increases the inelastic mean free path of the emitted electrons what makes HAXPES a non-destructive bulk sensitive probe for solid state research, especially studies of buried layers. Magnetoelectronic properties such as exchange splitting in ferromagnetic materials as well as the macroscopic magnetic ordering can be studied by magnetic circular dichroism in photoemission (MCDAD). In the present work MCDAD was integrated into HAXPES to explore the magnetic phenomena in deeply buried layers of the complex multilayer structures. In turn, direct measurements of electron spins of ferromagnets always attracted much attention but up to date have been limited by the surface sensitivity of the developed techniques. The last part of the work presents the results of the successfully performed spin-resolved HAXPES experiment using a spin polarimeter of the SPLEED-type on a buried magnetic layer.

Dr. Xeniya Kozina is a postdoctoral fellow at Japan Synchrotron Radiation Research Institute (JASRI), Spring-8. Xeniya has obtained her doctoral degree in physics from Johannes Gutenberg-Universität Mainz in 2012. Her research has been focused on studies of novel materials by application of hard x-ray photoelectron spectroscopy.