Tailoring of creep regime domain wall dynamics in perpendicularly magnetized Pd/Co/Pd trilayers

Understanding magnetic domain wall (DW) dynamics is vital for improving the performance of heavy metal /ferromagnet based spintronic based devices. Pd/Co/Pd multilayers hosting perpendicular magnetic anisotropy and interfacial Dzyaloshinskii-Moriya interaction are prototypes for high density magnetic memory devices. This work presents the creep regime DW dynamics in Pd/Co/Pd trilayers with Ta buffer layer excited by symmetric field-induced domain wall motion (FIDWM) using Kerr microscopy. A large systematic increment of DW velocity with increasing Co layer thickness has been observed. The DW width increases and becomes rough with larger Co layer content due to enhanced magnetostatic energy and a decrease of the effective anisotropy constant Keff. Hard X-ray photoemission spectroscopy (HAXPES) reveals the presence of alloying at interfaces of Co/Pd. The asymmetry in magnetic circular dichroism HAXPES at the Pd 3d edge pictures the induced magnetic moment in Pd which is consistent with the larger saturation magnetization obtained from vibrating sample magnetometry. X-ray absorption near edge spectroscopy performed in out-of-plane and in-plane geometry shows the disordered nature of Co local environment with interdiffusion of Pd atoms in to Co causing an asymmetry in the bonds.