Magnetic dichroism in angular resolved hard X-ray photoelectron spectroscopy from buried magnetic layers

Abstract

This work reports on the measurement of magnetic dichroism in angular-resolved photoelectron spectroscopy from in-plane magnetized buried thin films. The high bulk sensitivity of hard X-ray photoelectron spectroscopy (HAXPES) in combination with circularly polarized radiation enables the investigation of the magnetic properties of buried layers. Angular distributions of high kinetic energy (7-8 key) photoelectrons in a range of about 600 were recorded in parallel to the energy distribution. Depending on purpose, energy and angular resolutions of 150-250 meV and 0.17-2 degrees can be accomplished simultaneously in such experiments. Experiments were performed on exchange-biased magnetic layers covered by thin oxide films. More specifically, the angular distribution of photoelectrons from the ferromagnetic layer Co2FeAl layer grown on MnIr exchange-biasing layer was investigated where the magnetic structure is buried beneath a MgO layer. Pronounced magnetic dichroism is found in the Co and Fe 2p states for all angles of emission. A slightly increased magnetic dichroism was observed for normal emission in agreement with theoretical considerations. (C) 2013 Elsevier B.V. All rights reserved