FePt nanocrystals embedded in methylmethacrylate polymers

A simple, controlled and reproducible procedure is reported to obtain polymerized methylmethacrylate by embedding monodisperse Fe60Pt40 nanoparticles. The magnetic properties of the composite material can be controlled by the magnetic properties and the concentration (up to 0.3 wt%) of the starting nanoparticle dispersions. SQUID magnetometry measurements of FePt-doped methylmethacrylate polymers show superparamagnetic behavior at room temperature confirming the homogeneous particle distribution and the non-occurrence of agglomerates inside the polymeric matrix also observed by transmission electron microscopy. Even at the highest concentration the average particle distances are so large that no particle interactions play a role.