Magnetic states in low-pinning high-anisotropy material nanostructures suitable for dynamic imaging

Abstract

We present magnetic domain states in a material configuration with high (perpendicular) magnetic anisotropy and particularly low magnetic pinning. This material, a B-doped Co/Pt multilayer configuration, exhibits a strong magnetic contrast in x-ray transmission experiments, making it apt for dynamic imaging with modern synchrotron techniques, providing high spatial and high temporal resolution simultaneously. By analyzing the static spin structures in nanodisks at variable external fields, we show that CoB/Pt multilayers exhibit low enough domain wall pinning to manipulate the domain pattern with weak stimuli and in particular to move domains and domain walls. We demonstrate in a proof-of-principle experiment using pump-probe x-ray holographic imaging that moderate magnetic fields can induce elastic and deterministic and hence repeatable small variations of the domain configuration in CoB/Pt multilayers, which is the key to perform high-resolution imaging of the domain wall motion to gain insight to the details of the local magnetization dynamics.