Controlled domain wall manipulation in rapidly solidified amorphous submicronic wires

Abstract

Rapidly solidified submicronic amorphous glass-coated wires are unique materials due to their specific combination of reduced diameters, large sample length, and bistable magnetic behavior, of interest for sensing and magnetic logic applications due to their fast-moving magnetic domain walls. Here we report on the interaction of such domain walls moving within amorphous (Co0.94Fe0.06)72.5Si12.5B15 glass-coated submicronic wires with nearly zero magnetostriction. The main part of the complex experimental set-up includes multiple pick-up coils evenly distributed along a sample and two nucleation coils placed at its ends. If there is no signal in the nucleation coils, the magnetization switches starting from one end to the other, with a single moving domain wall being sequentially detected by the pick-up coils. Magnetization reversal can be initiated at both wire ends by means of nucleation fields generated using the corresponding nucleation coils. By adjusting the amplitudes of these fields, one can guide the two associated domain walls to move towards each other and to interact in any desired place along the submicronic amorphous sample. Hence, it is possible to control with accuracy the precise individual domain walls that interact on the wire axis, and with a certain precision, the location in which the two domain walls would interact. The collision of the domain walls gives rise to a double amplitude peak in the pick-up coil that detects it. The results show that the interaction of domain walls in amorphous submicronic wires is completely controllable, which is significant for their future applications.