Magnetic anisotropy in Fe3O4-PVA nanocomposites as a result of Fe3O4-nanoparticles chains formation

To study the nature of anisotropy effects in samples of polymer (PVA) films containing nanoparticles of magnetite the depth selective conversion Mossbauer spectroscopy (for layer-by-layer phase and magnetic analysis), saturation isothermal remanent magnetization (SIRM) and natural remanent magnetization measurements (NRM) in three mutual-orthogonal directions and atomic force microscopy were used. These investigations revealed formation of in plane direction of linear Fe3O4 nanoparticles chains and their number increase with nanoparticles concentration growth in the samples. Significant influence of polymer matrix on macroscopic magnetic properties was revealed from the temperature dependences of saturation magnetization and Mossbauer spectra. (C) 2005 Elsevier B. V. All rights reserved.