Propagation dynamics of the Bloch-type domain wall on CoFeB nanostripes driven by a nanosecond magnetic pulse

Abstract

Despite the abundance of research on the dynamics of magnetic domain walls (DW) on thin-film media, in-depth discussions regarding the behavior around the so-called Walker breakdown phenomenon are still scarce. In this work, propagation dynamics of the Bloch-type DW on CoFeB nanostripes with perpendicular anisotropy driven by a nanosecond magnetic pulse are investigated using micromagnetic simulation. It is found that on smaller nanostripes, the Walker breakdown corresponds with the oscillatory motion of the DW. On larger nanostripes, the formation of a Bloch-line with previously unreported behavior can be observed for magnetic pulses above HWB. Using a nanosecond field pulse instead of a continuous external field may allow for more direct control over the oscillatory DW motion and nucleation of the Bloch-line. A deeper understanding of the dynamics of the Bloch-type DW and its correlation to the applied nanosecond pulse may lead to better control of the DW for future spintronic devices.