PUB - Publikationen an der Universität Bielefeld

Reassembly of alpha-cobalt hydroxide nanosheets in the presence of citrate-capped gamma-Fe2O3 nanoparticles yields a-cobalt hydroxide-gamma-Fe(2)O(3 )hybrid in which the nanoparticles are trapped between the nanosheets. Thermal decomposition of the hybrid yields the Co3O4-gamma-Fe2O3 heterostructure. While the saturation magnetization (M-s) of gamma-Fe2O3 is preserved in the Co3O4-gamma-Fe(2)O(3 )heterostructure, the interface between the oxides in the heterostructure enhances the coercive field (H-C) to a large extent. The coercivity persists even above the Neel temperature of Co3O4 with the blocking temperature increased beyond room temperature. The unique morphology of the heterostructure wherein the Co3O4 and gamma-Fe2O3 particles are fused together to form a larger network leading to strong interparticle interactions, diffusion of Co atoms into the surface of gamma-Fe(2)O(3 )particles, and strain at the interfaces appear to be the reasons behind the improved magnetic behavior.