Spin-dependent conductivity and EPR study of undoped and doped poly (tertiarybutylisothianaphthene)

Measurements of spin-dependent conductivity (SDC) at both 9.67 GHz and 94 MHz and electron paramagnetic resonance (EPR) at 9.8 GHz have been made on undoped and doped poly (tertiarybutylisothianaphthene). Although doping increases the d.c. conductivity, σ, by about 30 times, there is little change in either the shape or intensity of the EPR spectrum. A resonant increase in conductivity is observed and the maximum fractional change in σ is about 10−5 at both 9.67 GHz and 94 MHz for all samples.