| Shaped magnetic ceramic materials have been prepared through the pyrolysis of a crosslinked poly(ferrocenylsilane) network, in greater than 90% ceramic yields up to 1000°C. The ceramics consisted of α-Fe nanoparticles embedded in a SiC/C matrix. Variation of pyrolysis temperature and time gave materials containing α-Fe nanoparticles of differing sizes resulting in materials with different magnetic and electronic properties. Variation of pyrolysis atmosphere provided further control over ceramic structure and composition.; The formation of iron based nanostructures has been demonstrated through the pyrolysis of fcSiMe2 and fcSi(CH2)3 inside the channels of a well ordered hexagonal mesoporous silica host, MCM-41. Ceramics derived from composite fcSiMe2/MCM-41, were superparamagnetic consisting of iron nanoparticles coated with a thin oxide layer. Pyrolysis studies on composite fcSi(CH2)3/MCM-41 resulted in smaller α-Fe nanoparticles than those obtained from the bulk pyrolysis of crosslinked poly(ferrocenylsilane), indicating that the silica host affected the nucleation and growth of the α-Fe nanoparticles. |
