Direct synthesis of nanocomposite of γ-Fe2O3 in the copolymer matrix of aniline-formaldehyde in presence of zinc ions

A novel approach for in-situ room temperature synthesis of magnetic nanocomposite of gamma-Fe2O3 is described. Fe-57 Mossbauer spectroscopy has been used to study its magnetic behavior. Observation of a relaxed sh line spectrum at room temperature and increase in hyperfine field values at 77 K are typical characteristics of magnetic microcrystalline particles. Interestingly, the studies at high temperature also show an increase in hyperfine magnetic field values, though it is quite unusual for small magnetic particles. This unusual behavior may, however, be attributed to some new kind of interaction between magnetic particles anal the polymer matrix, or between magnetic particles themselves caused by conformational changes in the copolymer matrix at higher temperatures. Moreover, these studies clearly indicate that both the polymer matrix and zinc ions play definite roles in the clustering of gamma-Fe2O3 particles, resulting in the phenomenon of relaxation over a wide range of temperatures. (C) 1998 Acta Metallurgica Inc.