Title : Influence of an additional magnetic video-pulse on the nuclear spin echo of nuclei located in the domain walls of magnets
Abstract:
The influence of an additional magnetic video-pulse on the nuclear spin echo in magnets is studied (on the example of cobalt micropowder and lithium-zinc ferrite) in two cases of its location relative to the second RF pulse, symmetrical and non-symmetrical [1]. In the first case, the decrease in the echo intensity is explained by the successive excitation of nuclei that abruptly change their position in the domain wall, and in the second case, due to the anisotropy of the hyperfine field. The effect of domain wall pinning on the dependence of echo signals on the amplitude and duration of a magnetic video-pulse is studied for the first time within the entire NMR spectrum of nuclei in domain walls.
Acknowledgment: This work was supported by Shota Rustaveli National Science Foundation of Georgia (SRNSFG) Grant # FR-22-7899.
Audience Take Away Notes:
- In this work, we study the nature of the NMR line from nuclei in the domain walls of the face-centered cubic (fcc) phase of cobalt. It has been found that the width of the NMR line is mainly due to the anisotropic component of the hyperfine field at the nuclei. The dependence of the pinning force of domain walls along the NMR spectrum of nuclei from the domain walls of fcc phase is studied in the case of symmetric and asymmetric action of a magnetic vileo-pulse (MVP). It is shown that the pinning force does not depend on the nature of the MVP effect on the spin echo and it is maximum at the center of the NMR line, where the MVP effect is minimal. In addition, it is shown that, along the NMR spectrum, the pinning force of the domain walls of the sample is inversely proportional to the MVP duration.
