Annual meeting of the Swiss Physical Society 2018

【805】 Imaging the magnetization reversal in strongly exchange-coupled bilayers

29 Aug 2018, 14:45

15m

CE 1 (EPFL)

Talk Magnetism and Spintronics at the Nanoscale Magnetism and Spintronics at the Nanoscale

Speaker

Dr Andrada-Oana Mandru (Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland)

Description

The magnetic reversal in perpendicular exchange-coupled systems consisting of a rare earth-based ferrimagnet (amorphous TbFe) and a transition metal-based ferromagnet (crystalline Co/Pt), can be surprisingly complex and different from conventional systems. We address the reversal mechanism locally by high-resolution MFM at 10K and in high fields. The TbFe layer alone reveals no change in its domain structure between 0 and 6T, allowing for a large field-span study of adjacent Co/Pt. The net moments of TbFe and Co/Pt are antiparallel aligned and as the field increases, the reversal of Co/Pt can be described by a three-stage magnetization process, where isolated grains switch over a wide field range. Unexpectedly, nanoscale inhomogeneities in both TbFe and Co/Pt are responsible for the observed behaviors.