Polyferrocenylsilane and magnetic ceramic microspheres

Microspheres comprised of polyferrocenylsilane with metal ions in the backbone of the polymer were synthesized. Upon oxidation, these polyferrocenylsilane microspheres (PFSMS) underwent electrostatic self-assembly with silica spheres to form composite core-shell particles. Thermal treatment of PFSMS transformed them, with shape retention, into ceramic microspheres containing α-Fe nanoclusters embedded within a silicon carbide-carbon matrix. Variation of the pyrolysis conditions led to ceramics with tunable magnetic properties from the superparamagnetic to the ferromagnetic states.