Interparticle interactions in perpendicularly and longitudinally oriented Ba-ferrite particulate media

Abstract

Interparticle interactions in perpendicularly and longitudinally oriented Ba-ferrite particulate media are studied experimentally. In order to make clear the effect of the orientation on the interparticle interactions in the media, the angular dependence of the interaction fields is measured by compensating for the demagnetizing fields at each measurement direction. It is found that perpendicularly and longitudinally oriented Ba-ferrite particulate media exhibit quite different angular dependence of the interaction fields, even though both of the media were prepared using the same dispersion. The study of the magnetic anisotropy derived from the interparticle interactions, which is significantly sensitive to the arrangement of the particles in the media, is considered to be useful for estimating the morphology of the magnetic layer of the media.

Magnetic anisotropy derived from interparticle interactions in CoPtCr/SiO2 granular thin film longitudinal media

“…If the angular dependence of the switching field distribution and the interaction fields of the medium are not known, however, the Preisach model cannot be applied to analyze the recording process. In a series of studies, [11][12][13][14][15]36 it was shown that the switching field distribution and the interaction fields in the medium can be separately obtained from the remanent magnetization curves. The method described here for evaluating the magnetic interaction anisotropy in the recording media should be helpful in the development of the Preisach hysteresis model.…”

“…For particulate media, the effect of interparticle interactions on the magnetic anisotropy has been verified by studying the angular dependence of the interaction fields. [11][12][13][14][15] A study of the effect of magnetostatic interactions on the magnetic anisotropy in granular media should lead to a better understanding of the magnetizing and demagnetizing process in the media and the effect of interactions on media noise.…”

Site occupancy and anisotropy distribution of Al substituted Ba‐ferrite with high coercivity

“…Based on the distributions of the Al 3+ ions on the five sites obtained from Mössbauer spectra, the origins of the remarkable increase in magnetic anisotropy field, magnetocrystalline anisotropy constant, and coercivity at 2 2 Experiments Nanocrystalline BaFe 12-x Al x O 19 (0.0 ≤ x ≤ 4.0) powders were fabricated by the solgel method [6 -8]. One of the advantages of using the sol-gel method is the lower annealing temperature that enables smaller grained powders to be grown (eg., nanocrystalline particles materials.…”

“…It has been intensively investigated as a high-density media for perpendicular and longitudinal recording, because of its high saturation magnetization, good chemical stability, and large magnetocrystalline anisotropy, as well as its mechanical hardness. For high-density magnetic recording, barium ferrite materials with high coercivity and small particle size are desired [1][2][3][4].…”

High magnetic performance in Al‐substituted BaFe 12 O 19 by a wet chemical process

“…To understand the magnetic recording behavior, it is important to study the coercivity, anisotropy, and saturation magnetization as well as small particle sizes. The coercivity is closely related to the magnetic anisotropy, which can be modified by substituting Fe 3+ with other ions [2][3][4]. Barium ferrite is substituted with other cations such as Co , and Al 3+ to reduce its coercivity and improve other magnetic properties [5][6][7].…”