Interface Magnetism of Magnetic Multilayers with Interfacial Dzyaloshinskii-Moriya Interaction*

Interfacial Dzyaloshinskii-Moriya Interaction (DMI) plays a significant role in stabilizing magnetic skyrmions at room temperature in multilayered films. Our previous results have shown magnetic skyrmions tuned with different top heavy metal (HM) layers in [Pt/Co/HM]_n varied in size, but the mechanism for this size tuning effect needs further study. Here we report the investigation of the interface magnetism in [Pt/Co/HM]_n multilayers using x-ray magnetic circular dichroism (XMCD) methods. [Pt(1.5nm)/Co(1nm)/HM(1nm)]_n multilayers (HM=Ir and Au) were deposited by DC magnetron sputtering with a Ta buffer on SiO₂/Si substrates. XMCD spectra were measured at the Advanced Photon Source of Argonne National Laboratory and the National Synchrotron Radiation Research Center (NSRRC) in Taiwan. The XMCD results show well-defined XMCD peaks at Ir L_2,3 and Au L₃ edges. The inversion of XMCD peaks with opposite magnetic fields demonstrates clear induced moments in Ir and Au multilayered thin films.