  Gamma - Iron Oxide prepared by sol -gel process was used to produce
nanocomposites with polyaniline of varying aniline concentrations. TEM shows
the presence of chain like structure for lower polyaniline concentration. The
room temperature hysteresis curves show finite coercivity of 160 Oe for all the
composites while the saturation magnetization was found to decrease with
increasing polymer content. ZFC - FC magnetisation measurements indicate high
blocking temperatures. It is believed that this indicates a strongly
interacting system, which is also shown by our TEM results. Monte Carlo
simulations performed on a random anisotropy model with dipolar and exchange
inteactions match well with experimental results.
