AFM tip-based cutting of grooves on permalloy nanowires for controlling the motion of magnetic domain walls

The research reported in this paper presents a new application of the AFM tip-based nanomachining process in the context of investigating the development of data storage devices. In particular, nanoscale grooves are machined with the tip of an AFM probe on the top surface of nanowires made of a ferromagnetic material. These grooves are cut with the purpose of creating artificial pinning sites for controlling the motion of magnetic domain walls within such nanowires. The experimental and computational results obtained when implementing this approach on permalloy nanowires 55 nm thick and 320 nm wide show that the strength of such artificial pinning sites increases with the increase in the depth of the machined grooves. It is anticipated that the application of AFM tip-based nanomachining in this context could contribute to the development of a variety of magnetic domain wall devices including those for logic function, data storage or sensor applications