Achieving a climate-neutral and circular economy by 2050 is a significant goal for Europe, emphasising innovation in clean energy and e-mobility. A major role in this transformation have permanent magnets (PM), vital in electric vehicles and renewable energy technologies. Despite their specialised market, they have a strategic impact on the EU's mobility sector and its dependence on imports. Given their critical role in numerous industrial and consumer applications, there is a pressing need for innovative approaches in their production and recycling.
For over 30 years, our research group at the Jožef Stefan Institute has led research and innovations in PMs, focusing on enhancing magnetic properties and efficient use of critical material resources. The most recent activities towards these goals are commonly referred to as grain-boundary engineering, focused on manipulating the non-magnetic two-dimensional-like grain boundary regions between the magnetic matrix grains to enhance the overall coercivity of the entire magnet. Simultaneously, we have explored various recycling and reprocessing strategies to enable the sustainable reuse of magnet waste into new functional magnets with only a little or negligible loss of overall magnetic performance. 
In this presentation, we will discuss several case studies illustrating how atomic-level structural and chemical analysis enhances our understanding of key physical and chemical mechanisms, which are essential for optimising magnetic performance and developing effective recycling strategies. For that purpose, we employed Advanced Transmission Electron Microscopy along with specialised analytical techniques such as Electron Energy-Loss Spectroscopy and Electron Holography, which provides quantitative magnetic characterisation at nanometer resolution. Among other findings, we will highlight how various grain-boundary structural refinement strategies during spark plasma sintering (SPS) influence the coercivity of Nd–Fe–B bulk magnets [1,2]. Additionally, we will discuss innovative electrochemical recycling techniques for sintered Nd–Fe–B PMs [3,4]. These techniques, which include direct recovery of the matrix phase and pure metal winning, are still emerging but have already shown promising results in our studies. 
 

Achieving a climate-neutral and circular economy by 2050 is a significant goal for Europe, emphasising innovation in clean energy and e-mobility. A major role in this transformation have permanent magnets (PM), vital in electric vehicles and renewable energy technologies. Despite their specialised market, they have a strategic impact on the EU's mobility sector and its dependence on imports. Given their critical role in numerous industrial and consumer applications, there is a pressing need for innovative approaches in their production and recycling.
For over 30 years, our research group at the Jožef Stefan Institute has led research and innovations in PMs, focusing on enhancing magnetic properties and efficient use of critical material resources. The most recent activities towards these goals are commonly referred to as grain-boundary engineering, focused on manipulating the non-magnetic two-dimensional-like grain boundary regions between the magnetic matrix grains to enhance the overall coercivity of the entire magnet. Simultaneously, we have explored various recycling and reprocessing strategies to enable the sustainable reuse of magnet waste into new functional magnets with only a little or negligible loss of overall magnetic performance. 
In this presentation, we will discuss several case studies illustrating how atomic-level structural and chemical analysis enhances our understanding of key physical and chemical mechanisms, which are essential for optimising magnetic performance and developing effective recycling strategies. For that purpose, we employed Advanced Transmission Electron Microscopy along with specialised analytical techniques such as Electron Energy-Loss Spectroscopy and Electron Holography, which provides quantitative magnetic characterisation at nanometer resolution. Among other findings, we will highlight how various grain-boundary structural refinement strategies during spark plasma sintering (SPS) influence the coercivity of Nd–Fe–B bulk magnets [1,2]. Additionally, we will discuss innovative electrochemical recycling techniques for sintered Nd–Fe–B PMs [3,4]. These techniques, which include direct recovery of the matrix phase and pure metal winning, are still emerging but have already shown promising results in our studies. 

In this study, we explore the challenge of creating anisotropic permanent magnets through the process of additive manufacturing, specifically using material extrusion (MEX). Typically, the production of anisotropic magnets requires the application of an external magnetic field, with the most cost-effective approach being the utilization of permanent magnets in a specific orientation to align the particles. However, when employing a filament-based 3D printer or material extruder, generating an adequate magnetic field presents certain difficulties. The simplest method involves printing directly atop a permanent magnet, as shown in previous studies. [1] However, this approach restricts the magnet's height due to the diminishing magnetic field with distance, eventually leading to a point where particle orientation ceases. Contrary to predictions, our observations revealed that the printed magnet not only sustains but also extends the magnetic field of the underlying permanent magnet. This results in a greater degree of anisotropy at distances further from the magnetic field source than initially anticipated. This discovery opens up new possibilities for more intricate designs, circumventing the limitations imposed by space constraints for permanent magnet placement by leveraging the magnetic field extension provided by the previously printed magnet.

Magnetic skyrmions are topologically-protected vortex-like magnetization patterns that can exist under special conditions in noncentrosymmetric structures. They might be applicable as carriers of classical and quantum information [1]. Whereas at the macroscopic level their existence is a finite-temperature phenomenon, theory predicts skyrmions with nanometer length scales at T = 0 [2].

An appropriate model, which can exhibit the respective phase, is a two-dimensional spin-1/2 Heisenberg lattice with the Dzyaloshiskii-Moriya interaction in an external field. A promising way to find the ground and excited states of the corresponding Hamiltonian is to apply a quantum algorithm. In this manner we have mapped the model-parameters phase diagram by performing the calculations with the variational quantum eigensolver (VQE) [3]. Although, due to a limited number of the working qubits, the investigated lattices have been too small to host a full skyrmion, the results clearly indicate the relation between the parameters, required for their existence.