Hysteresis of finite arrays of magnetic nanodots

Abstract

Hysteresis curves are investigated for finite arrays of $N\ifmmode\times\else\texttimes\fi{}N$ ferromagnetic nanodots subject to the dipole-dipole interaction ($N=2,\dots{}$,13). Spin arrangements up to $N=6$ are presented, which indicate the onset of bulklike behavior associated with odd $(N=5)$ and even $(N=6)$ systems. The effect of field misalignment on the hysteresis loops is also studied for $N=3,\dots{}$,6. The area ${A}_{N}$ of the hysteresis loop is studied as a function of $N$. ${A}_{N}\ensuremath{-}{A}_{\ensuremath{\infty}}$ approximately scales as ${N}^{\ensuremath{-}3}{2}}$ for $N$ odd and as ${N}^{\ensuremath{-}2}$ for $N$ even.