Influence of the Distance between Nanoparticles in Clusters on the Magnetization Reversal Process

Abstract

Fourfold magnetic nanoparticles, created from nanowires or in the form of an open square, offer the possibility of creating quaternary memory devices with four unambiguously distinguishable stable states at remanence. This feature, however, has been simulated for single magnetic nanoparticles or clusters with interparticle distances similar to the nanoparticle dimensions. For the possible use in bit-patterned media, it is important to understand the scaling behavior of the stability of the additional intermediate states with the interparticle distance. The paper investigates exemplarily nanoparticles of two shapes which were found to be optimum to gain four states at remanence. For clusters of these particles, the probability of reaching the additional intermediate states in all particles in the same field region is strongly reduced with decreased interparticle distance. The differences between both shapes indicate possible solutions for this problem in the form of new nanoparticle shapes.

Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization

“…In addition, a cation reordering was reported to occur in magnetite above 427 • C, corresponding to a gradual transformation from disordered to partially ordered configuration of magnetite [84]. These structural and magnetic effects may also have influenced the hysteresis loop shapes, in addition to the strong mass and volume loss; the latter resulting from an overproportioned shortening of the fibers as compared to the diameter increase, depicted in Figures 4 and 5, of the fibers during stabilization and carbonization [78][79][80], which automatically reduced the distances between neighboring nanoparticles and thus influenced their collective magnetic characteristics [85]. Figure 8 shows a comparison of nanofiber mats and thin films, prepared from PAN with both magnetic nanoparticles used in this study.…”

Micromagnetic Simulation of Vortex Development in Magnetic Bi-Material Bow-Tie Structures

“…Our recent simulations concentrate on individual nano-elements, before in a future simulation arrays of these structures will be modeled. Recent simulations of iron nanoparticles revealed that for inter-particle distances similar to the particle diameters, the influence of interactions with neighboring particles is relatively small [38,39], so that simulating individual elements firstly can be expected to be sufficient for a first comparison with the experiment.…”