Direct-write of free-form 3D nanostructures with controlled magnetic frustration

TL;DR

This paper introduces a novel direct-write method for fabricating free-form 3D ferromagnetic nanostructures with controlled magnetic frustration, enabling advanced studies and applications in magnetic systems and materials engineering.

Contribution

It presents a new fabrication technique for 3D nanostructures with precise magnetic control, surpassing previous 2D limitations and allowing integration of diverse materials.

Findings

Successfully fabricated freestanding 3D magnetic nano-architectures.

Measured magnetic stray fields and analyzed switching behavior.

Demonstrated integration of different material properties in 3D structures.

Abstract

Building nanotechnological analogues of naturally occurring magnetic structures has proven to be a powerful approach to studying topics like geometry-induced magnetic frustration and to provide model systems for statistical physics. Moreover, it practically allows to engineer novel physical properties by realizing artificial lattice geometries that are not accessible via natural crystallization or chemical synthesis. This has been accomplished with great success in the field of two-dimensional artificial spin ice systems with important branches reaching into the field of magnetic logic devices. Although first proposals have been made to advance into three dimensions (3D), established nanofabrication pathways based on electron beam lithography have not been adapted to obtain free-form 3D nanostructures. Here we demonstrate the direct-write fabrication of freestanding ferromagnetic 3D nano-architectures with full control over the degree of magnetic frustration. By employing micro-Hall sensing, we have determined the magnetic stray field generated by our free-form structures in an externally applied magnetic field and we have performed micromagnetic and macro-spin simulations to deduce the spatial magnetization profiles in the structures and analyze their switching behavior. Furthermore we show that the magnetic 3D elements can be combined with other 3D elements of different chemical composition and intrinsic material properties.