NMR Spin Echo Study of Domain Wall Pinning in Magnets in Combination with an Additional Magnetic Video-Pulse

Abstract

NMR spin echo at application of an additional magnetic video-pulse is a convenient method to study the domain wall pinning in magnetic materials. Domain wall (DW) pinning is the critical amplitude of the magnetic video-pulse (MVP) below which the DW is fixed. For its assessment, two alternative NMR methods were chosen. In the first case, the pinning of DW was measured by the action of MVP on a two-pulse echo signal, and in the second one, the pinning was measured at the combined action of MVP and radiofrequency (RF) pulses on the nuclear spin system in DW during the process of formation a single-pulse echo, by means of generation of the so-called magnetic echo signal. DW pinning was studied by these two methods in magnets (lithium-zinc ferrite and cobalt micropowder samples).

Keywords

• Nuclear spin echo
• Magnetic video-pulse
• Two-pulse echo
• Domain wall mobility
• Pinning.

References

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