Abstract
We report the crossover for the microwave dielectric constant of camphor-sulfonic-acid-doped polyaniline prepared in m-cresol from very large room-temperature negative values to large positive ones with decreasing temperature below Ts∼20 K. We attribute this change to the transition from a phonon-controlled metallic state to a nonmetallic state with localized carriers and hopping transport below Ts. Electronically, one-dimensional chains that couple the three-dimensional crystalline regions are likely central for understanding the origin of this transition as weak localization. At T<Ts we also observed an increase in the thermoelectric power and a linear decrease in the reduced activation energy for dc conductivity.
Original language | English |
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Pages (from-to) | 12226-12229 |
Number of pages | 4 |
Journal | Physical Review B |
Volume | 50 |
Issue number | 16 |
DOIs | |
Publication status | Published - 1994 |
Externally published | Yes |
ASJC Scopus subject areas
- Condensed Matter Physics