TY - JOUR

T1 - Finite dipolar hexagonal columns on piled layers of triangular lattice

AU - Matsushita, Katsuyoshi

AU - Sugano, Ryoko

AU - Kuroda, Akiyoshi

AU - Tomita, Yusuke

AU - Takayama, Hajime

PY - 2007/3

Y1 - 2007/3

N2 - We have investigated, by the Monte Carlo simulation, spin systems which represent moments of arrayed magnetic nanoparticles interacting with each other only by the dipole-dipole interaction. In the present paper we aim the understanding of finite size effects on the magnetic nanoparticles arrayed in hexagonal columns cut out from the close-packing structures or from those with uniaxial compression. In columns with the genuine close-packing structures, we observe a single vortex state which is also observed previously in finite two-dimensional systems. On the other hand in the system with the inter-layer distance set 1 / sqrt(2) times of the close-packing one, we found ground states which depend on the number of layers. The dependence is induced by a finite size effect and is related to a orientation transition in the corresponding bulk system.

AB - We have investigated, by the Monte Carlo simulation, spin systems which represent moments of arrayed magnetic nanoparticles interacting with each other only by the dipole-dipole interaction. In the present paper we aim the understanding of finite size effects on the magnetic nanoparticles arrayed in hexagonal columns cut out from the close-packing structures or from those with uniaxial compression. In columns with the genuine close-packing structures, we observe a single vortex state which is also observed previously in finite two-dimensional systems. On the other hand in the system with the inter-layer distance set 1 / sqrt(2) times of the close-packing one, we found ground states which depend on the number of layers. The dependence is induced by a finite size effect and is related to a orientation transition in the corresponding bulk system.

KW - Dipole-dipole interaction

KW - Finite size effect

KW - Magnetic nanoparticles

KW - Monte Carlo simulation

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U2 - 10.1016/j.jmmm.2006.10.426

DO - 10.1016/j.jmmm.2006.10.426

M3 - Article

AN - SCOPUS:33847267332

VL - 310

SP - 1416

EP - 1418

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

SN - 0304-8853

IS - 2 SUPPL. PART 2

ER -