Edge-modulated perpendicular magnetic anisotropy in [Co/Pd]n and L10-FePt thin film wires

TL;DR

This study investigates how edge thickness modulation in nanostructured magnetic thin films affects their perpendicular magnetic anisotropy, revealing opposite behaviors in different material systems through experimental and modeling approaches.

Contribution

It demonstrates the impact of edge tapering on magnetic anisotropy in [Co/Pd] and L10-FePt thin film wires, highlighting material-dependent effects.

Findings

Tapered edges reduce anisotropy in [Co/Pd]20 wires, leading to earlier reversal.

Tapered edges increase anisotropy in L10-FePt wires, affecting reversal behavior.

Edge modulation significantly influences magnetic reversal processes.

Abstract

Thickness modulation at the edges of nanostructured magnetic thin films is shown to have important effects on their perpendicular magnetic anisotropy. Thin film wires with tapered edges were made from [Co/Pd]20 multilayers or L10-FePt films using liftoff with a double layer resist. The effect of edge taper on the reversal process was studied using magnetic force microscopy and micromagnetic modeling. In [Co/Pd]20 the anisotropy was lower in the tapered edge regions which switched at a lower reverse field compared to the center of the wire. The L10-FePt wires showed opposite behavior with the tapered regions exhibiting higher anisotropy.