Nanoscale modification of magnetic properties for effective domain wall pinning.

Highlights • Spintronic devices based on domain wall (DW) devices have attracted great interest. • Domain wall racetrack memory has the potential for high-density storage. • Precise control of domain wall motion is a challenge. • We have studied the use of nanoscale compositional variation to pin the domain walls. • To achieve nanoscale compositional mixing, Cr crossbars were used. • Moreoever, we have carried out a novel minor loop investigation of magnetoresistance. • Minor loop study has provided a better understanding of the underlying physics. Abstract Magnetic domain wall memory technology, wherein the information is stored in magnetic domains of multiple magnetic nanowires, is a potential concept proposed to store the large amount of digital data in the near future, which is generated due to the widespread use of social media and computing devices. However, one of the technological challenges which remains to be solved in domain wall memory is the controllable pinning of the domain walls at the nanometer scale. Here, we demonstrate the possibility to stabilize domain walls with nanoscale modification of magnetic properties by using thermal diffusion of elements from crossbar configuration. We have inspected and evaluated the magnetic properties of the nanowires using Kerr microscopy. The pinning field induced by Cr diffusion of our Ni 80 Fe 20 nanowire was estimated to be about 8 kA/m as determined from minor loop (magnetoresistance vs. magnetic field) measurements. The proposed concept can potentially be used in future domain wall memory applications. [ABSTRACT FROM AUTHOR]