DESIGNING STRONG STABILITY IN NON-CRITICAL, RARE-EARTH-FREE L10-TYPE PERMANENT MAGNETS
The current portfolio of advanced permanent magnets heavily relies on rare earth elements that present significant supply chain vulnerabilities and environmental challenges. These issues drive research into alternative permanent magnet systems that could reduce or eliminate rare earth dependence.
Ferromagnetic L10-type compounds, with a high degree of atomic ordering, exhibit substantial magnetocrystalline anisotropy, making them strong candidates for permanent magnet applications. Among these, L10 FeNi (aka. tetrataenite) is particularly promising. Comprised exclusively of easily accessible, low-cost, and non-toxic elements, L10 FeNi exhibits intriguing hard magnetic properties with a high theoretical energy product ((BH)max = 42 MGOe (335 kJ/m3). However, laboratory-scale production of bulk tetrataenite remains unachievable due to the extremely low atomic mobilities (~ 1 atomic jump per 2,600 years) below its ordering temperature of 320 °C, where the atomically disordered fcc phase transforms into the L10-ordered structure. Tetrataenite is found naturally only in meteorites that form over billions of years.
Ongoing research efforts are being directed toward understanding the various factors that influence L10 phase formation and stability, including studies of other L10-forming proxy systems such as MnAl, FePd, FePt, etc. These investigations aim to develop fundamental insights that will ultimately guide the synthesis of tetrataenite on laboratory time scales.
MULTIDRIVER PROCESSING OF MAGNETOFUNCTIONAL MATERIALS
he performance of magnetic materials is extraordinarily sensitive to manufacturing details that can alter atomic environments and structures across multiple length scales. Control of this aspect is investigated via an integrated experimental-computational approach to understand the roles of applied thermal, magnetic and/or strain fields in the development of magnetofunctional materials. Specifically, we examine the effects of “MultiDriver Processing” – novel applications of passive magnetic field and/or mechanical stress during thermal treatment – as a means to control phase selection and transformations in select magnetofunctional material systems. Results are anticipated to furnish engineering guidance to advance high-efficiency, low-energy manufacturing processes for technologically significant magnetic systems, with applications across automotive, aerospace, clean energy, and biomedical fields.
USING MAGNETISM TO PROMOTE NEUROREGENERATION
This interdisciplinary study, bringing magnetism and biomedicine, aims to accelerate and guide neuroregeneration using magnetic attributes to influence neural cell behavior, advancing next-generation peripheral nerve repair. Specifically, the approach combines mild, static, passively applied magnetic fields with a novel glass-coated magnetic microwire to deliver both magnetic and topographical stimulation to neuron cells. This unique microwire, with diameters up to 100 micrometers, features a metallic magnetic core that offers intriguing magnetic responses, encased in a glass shell that provides excellent biocompatibility.
Context: Human peripheral nervous system (PNS) injury is a leading cause of disabilities and can severely impact patients’ quality of life. Current research in this field encompasses strategies that use various types of external stimulations (chemical, electrical, topographical, etc.) to accelerate and guide neuroregeneration (regrowth of nerve tissues and cells). This study contributes a novel magnetic approach to enhance existing strategies and improve outcomes for nerve repair.
This work is conducted in collaboration with Prof. Koppes (Ryan and Abigail) (Chemical Engineering, NU) and Prof. Manuel Vázquez (Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC).
RARE-EARTH-FREE MATERIALS FOR MAGNETIC REFRIGERATION
Magnetocaloric effect (MCE) refers to the reversible adiabatic temperature change in a magnetic material through exposure to a varying magnetic field. This phenomenon forms the basis of magnetic refrigeration, an environmentally friendly cooling method offering higher energy efficiency than traditional vapor-compression systems. Due to economic and geopolitical factors, there is an increasing demand within the scientific community to identify and explore cost-effective, earth-abundant magnetic materials. One such candidate is the 1-2-2 type intermetallic boride, AlFe2B2, which shows promise as a rare-earth-free magnetocaloric material for room-temperature thermal management applications. Research focuses on tailoring the magnetostructural phase transformation and magnetocaloric effect, evaluating the thermal and mechanical stabilities, and exploring novel efficient synthesis techniques for MCE working materials.
