Magnetic nanostructures for advanced technologies: fabrication, metrology and challenges

Abstract

Magnetic nanostructures are an integral part to many state-of-the-art and emerging technologies. However, the complete path from parts (the nanostructures) to the manufacturing of the end products is not always obvious to students of magnetism. The paper follows this path of the magnetic nanostructure, and explains some of the steps along the way: What are the technologies that employ magnetic nanostructures? How are these nanostructures made? What is the physics behind the functional parts? How are the magnetic properties measured? Finally, we present, in our view, a list of challenges hindering progress in these technologies.

Applications of exchange coupled bi-magnetic hard/soft and soft/hard magnetic core/shell nanoparticles

“…For example, the miniaturization trend in many magnetic devices is driving the state of the art magnetic devices to the tens of nm dimensions [11,16,[454][455][456][457]. Thus, to further push the limits of some magnetic devices core/shell nanoparticles could be an attractive alternative.…”

Imaging interfaces defined by abruptly varying internal magnetic fields by means of scanned nanoscale spin wave modes

“…2 10 15 He cm -2 [22][23][24]. We find that ion irradiation alters the saturation magnetization of the Py film increasing it to with a tunable probe-sample separation z.…”

Configuration dependent demagnetizing field in assemblies of interacting magnetic particles

“…, and since Tr(N dip )=0, according to equation (9), the following relation between the components of the dipolar fields is obtained,…”

“…8,9 For these systems one can assume that the height of the particles is very small compared with the lateral dimensions of the entire array and the volume containing the particles can be considered as an infinite thin film, so that N (10) and assuming particles with in-plane symmetry so that N x = N y and using N z = 4π − 2N x to express quantities in terms of N x , the effective demagnetizing field perpendicular to the plane (z) is…”

“…[5][6][7] Depending on their spatial disposition, and thus the shape or outer volume that contains the assembly, they form one, two or 3D heterostructures or composites. 5,6,[8][9][10] The magnetic properties of a single isolated particle are mainly governed by the shape and magnetocrystalline anisotropy and eventually a magnetoelastic contribution. In an assembly of many of such particles, their individual properties are further modified by the interaction field produced by the other particles.…”