Magnetic domain structure and dynamics in interacting ferromagnetic stacks with perpendicular anisotropy

TL;DR

This paper investigates the magnetic domain structures and their slow dynamics in ferromagnetic multilayers with perpendicular anisotropy, revealing how long-range magnetostatic interactions influence reversal processes and domain stability.

Contribution

It provides new insights into how magnetostatic interactions affect domain structure and reversal dynamics in coupled ferromagnetic multilayers with perpendicular anisotropy.

Findings

Magnetostatic fields cause mirroring domain structures and domain decoration.

Long-range interactions lead to ultra-slow domain dynamics even without external fields.

Harder layers reverse more rapidly under high magnetic field pulses due to these interactions.

Abstract

The time and field dependence of the magnetic domain structure at magnetization reversal were investigated by Kerr microscopy in interacting ferromagnetic Co/Pt multilayers with perpendicular anisotropy. Large local inhomogeneous magnetostatic fields favor mirroring domain structures and domain decoration by rings of opposite magnetization. The long range nature of these magnetostatic interactions gives rise to ultra-slow dynamics even in zero applied field, i.e. it affects the long time domain stability. Due to this additionnal interaction field, the magnetization reversal under short magnetic field pulses differs markedly from the well-known slow dynamic behavior. Namely, in high field, the magnetization of the coupled harder layer has been observed to reverse more rapidly by domain wall motion than the softer layer alone.