Giant magnetoresistance of Fe3 O4 -polymethylmethacrylate nanocomposite aligned fibers via electrospinning

This paper describes the results of investigations on giant negative magnetoresistance (GMR) in nanocomposite aligned fibers prepared using electrospinning. The nanocomposite contains polymethylmethacrylate (PMMA) matrix and the nanoparticles of polymer (PMMA) grafted magnetite, Fe3 O4 (PGM). Even for the low magnetic field (1 T) a GMR of about 50% was observed for low loading (5 wt %) of PGM at room temperature. The fibers were characterized using scanning electron microscope and high resolution transmission electron microscope. X-ray diffraction (XRD) patterns were recorded for clean PMMA fibers, PMMA granules, and PGM nanoparticles. The dc conductivity was calculated from the I-V characteristics for the fibers at room temperature. © 2007 American Institute of Physics.