TY - JOUR
T1 - Effect of dipole interaction on microwave assisted magnetization switching
AU - Okamoto, S.
AU - Kikuchi, N.
AU - Kitakami, O.
AU - Igarashi, M.
N1 - Funding Information:
This work is partially supported by the “Research and Development for Next-Generation Information Technology of MEXT,” “Special Education and Research Expenses, Post-Silicon Materials and Devices Research Alliance,” and Grant-in-Aid for Scientific Research from MEXT, the Storage Research Consortium in Japan, and The Murata Science Foundation. FIG. 1. (a) Schematic illustration of a row of three particles R, C, and L. (b) Illustrations of various MP and MG combinations and media types modeled by the various applications of ac and dc fields. FIG. 2. Calculated 2D maps of the switching conditions for particles L, C, and R as functions of H dc / H k and f ac . (a)–(d) show the results for cases I, II, III, and IV, respectively. FIG. 3. Time dependent trajectories of in-plane and perpendicular components of magnetization m y and m z of (a) particle C and (b) particle R for case III. FIG. 4. Calculated 2D maps of the switching conditions for particles L, C, and R with variation of Δ K u / K u C as functions of H dc / H k i ( i = L , C, and R) and f ac . (a) is for Δ K u / K u C = 0 , (b) is for Δ K u / K u C = 0.05 , and (c) is for Δ K u / K u C = 0.1 . FIG. 5. H sw of particles L, C, and R normalized by H k i ( i = L , C, and R) as a function of Δ K u / K u C . FIG. 6. Calculated 2D maps of the switching conditions for particles C with variation of θ H as functions of H dc / H k C and f ac . FIG. 7. H sw of particles L, C, and R normalized by H k i ( i = L , C, and R) as a function of θ H .
PY - 2010
Y1 - 2010
N2 - Microwave assisted switching (MAS) of magnetization has attracted much attention as an alternative technique for future ultrahigh density magnetic recording. In this study, to elucidate the effect of magnetostatic interparticle interaction on MAS, we have calculated the switching behavior for a row of three uniaxial magnetic particles as a simplest case. When a dc field is applied only to one particle of the row in an ac field, MAS selectively occurs in the particle and not in the neighboring particles. This behavior may be very effective to realize narrow track recording without adjacent track erasure problem by downsizing a dc field source below an ac source. It has been also found that when both ac and dc fields are applied to all the particles, coherent magnetization precession is cooperatively induced in all the particles due to dipole-dipole interaction among neighboring particles, resulting in significant reduction of the switching field. This coherent magnetization precession is not only effective to reduce the switching field but also to suppress the effect of magnetic anisotropy dispersion, suggesting the effectiveness of MAS in granular recording media.
AB - Microwave assisted switching (MAS) of magnetization has attracted much attention as an alternative technique for future ultrahigh density magnetic recording. In this study, to elucidate the effect of magnetostatic interparticle interaction on MAS, we have calculated the switching behavior for a row of three uniaxial magnetic particles as a simplest case. When a dc field is applied only to one particle of the row in an ac field, MAS selectively occurs in the particle and not in the neighboring particles. This behavior may be very effective to realize narrow track recording without adjacent track erasure problem by downsizing a dc field source below an ac source. It has been also found that when both ac and dc fields are applied to all the particles, coherent magnetization precession is cooperatively induced in all the particles due to dipole-dipole interaction among neighboring particles, resulting in significant reduction of the switching field. This coherent magnetization precession is not only effective to reduce the switching field but also to suppress the effect of magnetic anisotropy dispersion, suggesting the effectiveness of MAS in granular recording media.
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U2 - 10.1063/1.3298929
DO - 10.1063/1.3298929
M3 - Article
AN - SCOPUS:76949105529
SN - 0021-8979
VL - 107
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 3
M1 - 033904
ER -