Asymmetric magnetic dots: A way to control magnetic properties

Abstract

We have used Monte Carlo simulations to investigate the magnetic properties of asymmetric dots as a function of their geometry. The asymmetry of round dots is produced by cutting off a fraction of the dot and is characterized by an asymmetry parameter $\alpha$. This shape asymmetry has interesting effects on the coercivity ($H_c$), remanence ($M_r$), and barrier for vortex and C- state formation. The dependences of $H_c$ and $M_r$ are non monotonic as a function of $\alpha$ with a well defined minima in these parameters. The vortex enters the most asymmetric part and exits through the symmetric portion of the dot. With increasing $\alpha$ the vortex formation starts with a C-state which persists for longer fields and the barrier for vortex exit diminishes with increasing asymmetry, thus providing control over the magnetic chirality. This implies interesting, naively-unexpected, magnetic behavior as a function of geometry and magnetic field.

6 pages, 6 figures

References in corpus (3)

• Angular Dependence of Vortex Annihilation Fields in Asymmetric Co Dots
• Controllable switching of vortex chirality in magnetic nanodisks by a field pulse
• Tailoring the magnetic properties of Fe asymmetric nanodots