Magnetic manipulation in Dy/Tb multilayer upon electron-irradiation

Abstract

Manipulation and control of defects triggered by an electron beam allow us to conduct defect engineering on layered materials. We investigate topologically stable helices within a [Dy(10 nm)/Tb(10 nm)]30 multilayer subjected to MeV electron(e)-irradiation up to a maximum fluence of 9.58 × 1018 e/cm2. As electrons can go through the sample homogeneously and with high penetration depth, they produce defects without doping. Our e-irradiation results indicate defect induced magnetic manipulation, which increases the blocking/freezing temperature of spin-frustrated interfaces by 4%. This increase implies an increase in the spin-cluster volume. Consequently, the reduced uncompensated pinning centres decrease the interfacial exchange bias coupling by 45%. Direct manipulation of pinning centres would thereby allow us to tailor spintronic devices in a clean way.