arXiv subjects

B. Leighton

Publications and source records attributed to B. Leighton.

3 recordsLinked to original sources

arXiv2011

Tailoring the magnetic properties of Fe asymmetric nanodots

Asymmetric dots as a function of their geometry have been investigated using three-dimensional (3D) object oriented micromagnetic framework (OOMMF) code. The effect of shape asymmetry of the disk on coercivity and remanence is studied. Angular dependence of the remanence and coercivity is also addressed. Asymmetric dots are found to reverse their magnetization by nucleation and propagation of a vortex, when the field is applied parallel to the direction of asymmetry. However, complex reversal modes appear when the angle at which the external field is applied is varied, leading to a non monotonic behavior of the coercivity and remanence.

cond-mat.mes-hall↗

arXiv2011

Asymmetric magnetic dots: A way to control magnetic properties

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 $α$. 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 $α$ 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 $α$ 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.

cond-mat.mes-hall↗

arXiv2010

Magnetic phase diagrams of barcode-type nanostructures

The magnetic configurations of barcode-type magnetic nanostructures consisting of alternate ferromagnetic and nonmagnetic layers arranged within a multilayer nanotube structure are investigated as a function of their geometry. Based on a continuum approach we have obtained analytical expressions for the energy which lead us to obtain phase diagrams giving the relative stability of characteristic internal magnetic configurations of the barcode-type nanostructures.

cond-mat.mes-hall↗