Timing and Spectral Diagrams of Magnetic Video-Pulse Excitation Influence on NMR Spin–Echo in Magnets

NMR methods are successfully used in obtaining the microscopic information on the internal magnetic structure and dynamical processes in magnets. The important application of NMR in magnets is also the investigation of structure and dynamics of domain walls. In this work, it is accomplished by observation of nuclear spin echo signals of nuclei arranged in domain walls of magnets at excitation by an additional magnetic video-pulse field. We present the first systematic study of timing and spectral diagrams of magnetic video-pulse influence on the NMR two-pulse echo in a number of magnets (ferromagnets, ferrites, half metals, intermetals). It is shown that the timing diagrams showing the dependence of two-pulse echo intensity on the temporal location of a magnetic video-pulse in respect to radio-frequency pulses and spectral diagram of this influence are defined mainly by local hyperfine field anisotropy and domain walls mobility. These diagrams could be used for the identification of the nature of NMR spectra in multidomain magnetic materials and to improve the resolution capacity of the NMR method in magnets.