Photocurable Hybrid Materials with High Magnetodielectric Coupling

Magnetodielectric materials are highly interesting inthe scopeof Internet of Things (IoT)-related devices such as antennas, sensors,and actuators, as they allow the magnetic control of the dielectricresponse. Among the different possible methods for their development,the combination of photocurable polymers and magnetic nanoparticlesallows more sustainable processes with high production velocities,room processing temperature, and the capability to fabricate a largevariety 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, includingcobalt ferrite oxide (CFO), magnetite (Fe3O4), and a neodymium iron boron alloy (NdFeB), have been developed.The influence of filler type and content on the photopolymerizationprocess, sample morphology, physicochemical properties, electricalconductivity, and magnetic properties has been investigated. Fillerdispersion 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 thecomposites. Materials with maximum magnetodielectric coefficients(MD %) as large as 28% have been obtained for the sample with 6% NdFeBfiller content, making these magnetic composites of paramount interestfor the fabrication of magnetodielectric devices in the context ofthe digital transition.