THE ENHANCEMENT EFFECT IN THE DOMAIN AND DOMAIN-WALL IN FE-57 NUCLEAR-MAGNETIC-RESONANCE

We observed both the nuclear magnetic resonance (NMR) signals from the domain and the domain wall in pure iron particles. In the multi-domai n state, the total signal was divided into the signal from the domain and that from the domain wall and the enhancement factors were evaluat ed separately. The average enhancement factors in the domain walls and the domains were estimated to be about 136 and 34, respectively, in z ero field, and remained constant in external dc field in the multi-dom ain state. In the single domain state, it was observed that the enhanc ement factor is inversely proportional to external field, and the reso nance frequency decreases linearly with external field. From the compa rative study between the magnetization curve and the variation curves of the domain wall signal and the resonance frequency with external fi eld, we showed that NMR could give useful information on the magnetiza tion process. (C) 1997 American Institute of Physics.