Shaped ceramics with tunable magnetic properties from metal-containing polymers

A shaped, magnetic ceramic was obtained from a metal-containing polymer net work, which was synthesized by thermal polymerization of a metal-containing organosilicon monomer. Pyrolysis of a cylinder, shape, or film of the meta l-containing polymer precursor produced a Low-density magnetic ceramic repl ica in high yield. The magnetic properties of the shaped ceramic could be t uned between a superparamagnetic and ferromagnetic state by controlling the pyrolysis conditions, with the particular state dependent on the size of i ron nanoclusters homogeneously dispersed throughout the carbosilane-graphit ic-silicon nitride matrix. These results indicate that cross-linked metal-c ontaining polymers may be useful precursors to ceramic monoliths with tailo rable magnetic properties.