Electrical conductivity measurements as a microprobe for structure transitions in polysiloxane derived Si–O–C ceramics

Polysiloxanes [RSiO1.5]n with R=CH3 (PMS) and C6H5 (PPS), respectively, were transformed to Si–O–C ceramics of variable composition and structure upon pyrolysis in inert atmosphere at 800–1500°C. The electrical conductivities of the Si–O–C ceramics in air were measured at room temperature by using a shielded two point configuration. In situ measurements of the dc-conductivity during the pyrolytic conversion from the polymer to the ceramic phase...