Tunable magnetism on the lateral mesoscale by post-processing of Co/Pt heterostructures

TL;DR

This paper demonstrates a method to locally tune the magnetic properties of Co/Pt heterostructures on the lateral mesoscale through post-processing, enabling control over coercivity and magnetization for potential micro-magnetic applications.

Contribution

It introduces a novel post-processing technique to control lateral magnetic properties of Co/Pt nano-structures, expanding the capabilities beyond vertical heterostructure engineering.

Findings

Post-processing induces hard-magnetic behavior in Co/Pt nano-stripes.

Coercive fields up to 850 Oe achieved.

Formation of CoPt L1$_{0}$ phase confirmed by TEM.

Abstract

Controlling magnetic properties on the nm-scale is essential for basic research in micro-magnetism and spin-dependent transport, as well as for various applications such as magnetic recording, imaging and sensing. This has been accomplished to a very high degree by means of layered heterostructures in the vertical dimension. Here we present a complementary approach that allows for a controlled tuning of the magnetic properties of Co/Pt heterostructures on the lateral mesoscale. By means of in-situ post-processing of Pt- and Co-based nano-stripes prepared by focused electron beam induced deposition (FEBID) we are able to locally tune their coercive field and remanent magnetization. Whereas single Co-FEBID nano-stripes show no hysteresis, we find hard-magnetic behavior for post-processed Co/Pt nano-stripes with coercive fields up to 850 Oe. We attribute the observed effects to the locally controlled formation of the CoPt L1$_{0}$ phase, whose presence has been revealed by transmission electron microscopy.