Photocurable Hybrid Materials with High Magnetodielectric Coupling

Magnetodielectric materials are highly interesting in the scope of Internet of Things (IoT)-related devices such as antennas, sensors, and actuators, as they allow the magnetic control of the dielectric response. Among the different possible methods for their development, the combination of photocurable polymers and magnetic nanoparticles allows more sustainable processes with high production velocities, room processing temperature, and the capability to fabricate a large variety of specific shapes with high resolution. In this context, photocurable magnetic hybrid materials based on polyurethane acrylate (PUA) and on different magnetic micro- and nanoparticles, including cobalt ferrite oxide (CFO), magnetite (Fe3O4), and a neodymium iron boron alloy (NdFeB), have been developed. The influence of filler type and content on the photopolymerization process, sample morphology, physicochemical properties, electrical conductivity, and magnetic properties has been investigated. Filler dispersion has also been studied by neutron scattering techniques, enabling the determination of the organization of the filler aggregates, which plays an essential role in the overall characteristics of the composites. Materials with maximum magnetodielectric coefficients (MD %) as large as 28% have been obtained for the sample with 6% NdFeB filler content, making these magnetic composites of paramount interest for the fabrication of magnetodielectric devices in the context of the digital transition.