Asymmetric magnetic domain wall motion in quasi-perpendicularly magnetized Pt/Co/Pt trilayer with interfacial Dzyaloshinskii-Moriya interaction

Abstract

Field-induced domain wall motion has been observed in quasi-perpendicularly magnetized Pt/Co/Pt trilayers with interfacial Dzyaloshinskii-Moriya interaction (iDMI) using differential Kerr microscopy method in the creep regime. An oblique angle sputter deposition technique had introduced a thickness gradient in one of the layers of a trilyer, results in a small tilt of magnetic anisotropy from the film normal. The tilt angle has been estimated in each trilayer by determining the shift in the out-of-plane magnetization hysteresis measurements under bias magnetic field applied along various in-plane directions. The effective in-plane field at the domain wall due to iDMI has been determined by decomposing the symmetric and asymmetric contributions of the domain wall motion. Furthermore, the asymmetric contribution has been decomposed into two contributions due to the tilted magnetic anisotropy and the exponentially decaying chiral damping. The nature of the asymmetric contribution owing to the tilted anisotropy was studied by the collective coordinate model and a functional form of the total asymmetric contribution has been determined and used to fit the asymmetric contribution.