PHYSICAL-PROPERTIES OF A MAGNETICALLY-ORIENTED CARBONACEOUS MESOPHASE

Diamagnetic susceptibility, electron spin resonance, and specific heat measurements have been made on a magnetically-oriented mesophase pitch. The diamagnetic anisotropy (χ⊥ - χ∥) was found to be -0.69 × 10-6emu CGSg-1 and the average susceptibility ̄gc = (2χ∥ + χ⊥) 3 = -0.73 × 10-6 emu CGS g-1. ESR measurements of the g-factor and linewidth confirmed the anistropic behavior and indicated free radical concentrations of ~1.2× 1019 g-1. The low-temperature specific heat results showed evidence of an anomalous linear term. A consideration of the magnitude of the susceptibility and atomic C H ratio suggests that the molecules consist of relatively small aromatic regions connected by aliphatic and aryl bridges. © 1979.