TEM Study of Current-Induced Domain Wall Motion in Cylindrical Nanowires: Towards 3D Magnetic Memory Devices

Modern information storage technology strives toward realizing 3D devices. A very promising idea for 3D magnetic memory, called vertical race-track memory, proposed in 2008, was to manipulate information by utilizing current-driven domain wall (DW) motion in magnetic nanowires (NWs) [1]. Specifically, magnetic domains, separated by DWs, represent bits of information, whereas DW position and motion (i.e. information storage and transfer) can be controlled by spin-polarized electric currents. The main challenge in realizing this idea comes from the standard micro-fabrication methods, which are highly effective for fabrication planar devices but very limited in capabilities when it comes to out-ofplane structures. One way to increase the memory density could be stacking of storage layers in a single device. This complicates significantly the fabrication process even for a small number of layers. Hence, there is a need for efficient alternative fabrication concepts.