Magnetic and magnetoresistance behaviors of particulate iron/vinyl ester resin nanocomposites

Magnetoresistance (MR) behavior of vinyl ester monomer stabilized iron nanoparticles and heat-treated vinyl ester resin nanocomposites reinforced with iron nanoparticles were investigated. Vinyl ester monomer serves as a coupling agent with one side covalently bound onto the nanoparticle surface by a displacement reaction and the other end copolymerized with extra vinyl ester resin to form a robust entity. The particle loading and type of material (polymer or carbonized polymer) have a significant effect on the magnetic and MR properties. The heat-treated nanocomposites follow a tunneling conduction. After reduction annealing, the obtained nanocomposites possess a room temperature MR of 8.3 % at a field of 90 kOe. (C) 2008 American Institute of Physics.