Synthesis Of Sifec Magnetoceramics From Reverse Polycarbosilane-Based Microemulsions

In this paper, we report the synthesis of iron-containing SiC(O) magnetoceramics using a reverse microemulsion technique. First, an aqueous iron nitrate solution as the internal phase and a polycarbosilane (PCS)-heptane solution as the continuous phase were emulsified in the presence of a surfactant to synthesize iron-containing PCS (Fe-PCS) reverse microemulsion systems. After the removal of water and heptanes, the Fe-PCS precursors were pyrolyzed at 6001-1200°C to produce magnetoceramics. The structures and magnetic properties of the ceramics obtained were characterized by using X-ray diffraction, transmission electron microscopy, electron probe microanalysis, and superconducting quantum interference device. The results showed that the ceramics contained Fe3Si nanoparticles, which dispersed in SiCO amorphous matrix. This unique structure makes the ceramics excellent soft ferromagnetic materials with a high magnetizability and negligibe hysteresis loops. © 2010 The American Ceramic Society