Nucleation and interactions of 360 degrees domain walls on planar ferromagnetic nanowires using circular magnetic fields

作者：Kaya F I; Sarella A; Wang D; Tuominen M; Aidala K E^*

来源：AIP Advances, 2016, 6(5): 055025.

DOI：10.1063/1.4953058

We propose a mechanism for nucleation of 360 degrees domain walls (DWs) on planar ferromagnetic nanowires, of 100 nm width, by using circular magnetic fields, and find the minimal spacing possible between 360 degrees DWs. The extent of the stray field from a 360 degrees DW is limited in comparison to 180 degrees DWs, allowing 360 degrees DWs to be spaced more closely without interactions than 180 degrees DWs, which is potentially useful for data storage devices. We use micromagnetic simulations to demonstrate the positioning of 360 degrees DWs, using a series of rectangular 16 x 16 nm(2) notches to act as local pinning sites on the nanowires. For these notches, the minimum spacing between the DWs is 240 nm, corresponding to a 360 degrees DW packing density of 4 DWs per micron. Understanding the topological properties of the 360 degrees DWs allows us to understand their formation and annihilation in the proposed geometry. Adjacent 360 degrees DWs have opposite circulation, and closer spacing results in the adjacent walls breaking into 180 degrees DWs and annihilating.

• 出版日期2016-5