Domain-wall resistance in CoFeB-based heterostructures with interface Dzyaloshinskii-Moriya interaction

We studied the domain-wall resistance in W/Ta/CoFeB/MgO heterostructures. The Ta layer thickness was varied to control the type of domain walls (DWs) via changes in the interfacial Dzyaloshinskii-Moriya interaction. The domain-wall resistance was nearly constant with changes in the Ta layer thickness. The anisotropic magnetoresistance, spin Hall magnetoresistance, and anomalous Hall effect contributed to the domain-wall resistance of the thick-Ta layer films. However, a discrepancy remains for the thin-Ta layer films, wherein chiral Neel-like DWs were observed. These results show the difficulty of studying the domain-wall type via resistance measurements. (C) 2018 The Japan Society of Applied Physics