Tailoring the Topological Hall Effect in Pt/Co/X (X = Ta, Re) thin films

Abstract

Electron transport combined with magnetism has gained more attention to the spintronics community in the last few decades. Among them, the topological Hall effect (THE), which arises due to the emergent magnetic field of a non-trivial object, is found to be a promising tool for probing the presence of skyrmions. A sizeable Dzyaloshinskii-Moriya interfacial interaction (iDMI) with reduced effective anisotropy can stabilize skyrmions in thin films. Recently, a large iDMI has been predicted in Pt/Co/Re thin film. Here, we investigate the influence of various magnetic interactions on the THE in perpendicularly magnetized Pt/Co/X (X = Ta, Re) thin films. The presence of skyrmions is confirmed via THE and magnetic force microscope (MFM) imaging. Notably, two distinct types of THE signals are observed in the different samples, which are explained using micromagnetic simulations. Our results reveal that exchange interaction, iDMI, effective anisotropy, and saturation magnetization contribute significantly in determining the variations in topological Hall resistivity behavior, which arise from different skyrmionic phases. These findings contribute to the development of novel material systems featuring different skyrmionic phases with potential applications in spintronics.