PMC:7503833 / 15568-17104 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/7503833","sourcedb":"PMC","sourceid":"7503833","source_url":"https://www.ncbi.nlm.nih.gov/pmc/7503833","text":"The second demonstration of the proposed scaling rules was a simulation of magnetization processes for the tetragonal box with magnetic anisotropy (K = 5 × 10−5 eV) directed along the z-axis. Magnetic field, also applied in the z-axis, ranged from 1.2 to −1.2 T in order to obtain a full hysteresis loop. The n parameter was equal to 100 and the remaining parameters of the system were the same as for the previous example (see Figure 5). In this configuration, a quadratic hysteresis loop was expected and obtained using the above-described procedure. Figure 6e shows a normalized magnetization (z-component of average magnetic moment) in a function of the applied external magnetic field, as shown in the graph in the center. Additionally, magnetic moment configurations in fields around the magnetization jump are presented as a background. It can be seen that the reverse magnetization process started from a “seed” nucleated on the top surface (Figure 6a) and then the domain expanded, reaching new saturation according to the direction of the external magnetic field. The Figure 6c depicts the growing domain responsible for the rapid magnetization change. This scenario was expected due to the fact that the magnetic moments on the top (or bottom) surface are more weakly coupled in comparison to the magnetic moments in the volume. Moreover, for this irregular shape and value of n, the dipolar interactions tend to reverse the directions of the magnetic moments, especially near the top and bottom surfaces (see also Figure 5).","tracks":[]}