Thermal transition behaviour of iron oxide–polypyrrole nanocomposites

Distinct thermal transitions have been observed in nanocomposites based on iron oxide–polypyrrole prepared by simultaneous gelation and polymerization process. The transition behaviour for various iron oxide–polypyrrole compositions was investigated with the help of differential scanning calorimetery. It has been observed that the samples show a magnetic to nonmagnetic transition at 410 °C. The presence of exothermic peak at 410 °C is a strong indication of magnetic transition corresponding to γ-Fe2O3 phase of iron oxide to a nonmagnetic α-Fe2O3 phase in these nanocomposites. However such a transition was not observed in nanocomposites containing lesser concentration of conducting polymer.