Abstract
The results of microwave dielectric constant (ε{lunate}mw) and dc conductivity (σdc) of doped polyaniline (PAN) samples in different charge delocation regimes are reported. With camphor culfonic acid doped PAN prepared in m-cresol solvent (PAN-CSA (m-cresol)) respresenting the most delocalized material, a negative ε{lunate}mw is measured indicating an intrinsic metallic state. The Drude model at low frequency is used to estimate a relatively small plasma frequency ωp {reversed tilde equals} 0.015 eV and an anomalously long scattering time τ {reversed tilde equals} 1.2 × 10-11 s. This τ implies the importance of phonon back scattering for the most delocalized electrons as expected for the open Fermi surface of a highly anisotropic metal. Depending on the crystallinity, there are two different charge localization regimes in PAN samples: uncoupled metallic islands and coupled "mesoscopic" metallic state. The three-dimensional nature of metallic state is demonstrated by the correlation of low temperature dielectric response with the parallel and perpendicular crystalline domain lengths obtained from x-ray data. The charge localization to delocalization transition dependence on the polymer processing will be discussed. We present the temperature dependent nonmetal-metal transition for some preparations of PAN-CSA (m-cresol). The intrinsic conductivity of metallic PAN is estimated to be ∼ 107 S/cm.
| Original language | English |
|---|---|
| Pages (from-to) | 251-254 |
| Number of pages | 4 |
| Journal | Synthetic Metals |
| Volume | 69 |
| Issue number | 1-3 |
| Publication status | Published - 1995 Mar 1 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Metals and Alloys
- Materials Chemistry
- Electronic, Optical and Magnetic Materials
- Mechanics of Materials
- Mechanical Engineering
- Polymers and Plastics
Cite this
Evolution of the conducting state of polyaniline from localized to mesoscopic metallic to intrinsic metallic regimes. / Joo, Jinsoo; Oh, E. J.; Min, G.; MacDiarmid, A. G.; Epstein, A. J.
In: Synthetic Metals, Vol. 69, No. 1-3, 01.03.1995, p. 251-254.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evolution of the conducting state of polyaniline from localized to mesoscopic metallic to intrinsic metallic regimes
AU - Joo, Jinsoo
AU - Oh, E. J.
AU - Min, G.
AU - MacDiarmid, A. G.
AU - Epstein, A. J.
PY - 1995/3/1
Y1 - 1995/3/1
N2 - The results of microwave dielectric constant (ε{lunate}mw) and dc conductivity (σdc) of doped polyaniline (PAN) samples in different charge delocation regimes are reported. With camphor culfonic acid doped PAN prepared in m-cresol solvent (PAN-CSA (m-cresol)) respresenting the most delocalized material, a negative ε{lunate}mw is measured indicating an intrinsic metallic state. The Drude model at low frequency is used to estimate a relatively small plasma frequency ωp {reversed tilde equals} 0.015 eV and an anomalously long scattering time τ {reversed tilde equals} 1.2 × 10-11 s. This τ implies the importance of phonon back scattering for the most delocalized electrons as expected for the open Fermi surface of a highly anisotropic metal. Depending on the crystallinity, there are two different charge localization regimes in PAN samples: uncoupled metallic islands and coupled "mesoscopic" metallic state. The three-dimensional nature of metallic state is demonstrated by the correlation of low temperature dielectric response with the parallel and perpendicular crystalline domain lengths obtained from x-ray data. The charge localization to delocalization transition dependence on the polymer processing will be discussed. We present the temperature dependent nonmetal-metal transition for some preparations of PAN-CSA (m-cresol). The intrinsic conductivity of metallic PAN is estimated to be ∼ 107 S/cm.
AB - The results of microwave dielectric constant (ε{lunate}mw) and dc conductivity (σdc) of doped polyaniline (PAN) samples in different charge delocation regimes are reported. With camphor culfonic acid doped PAN prepared in m-cresol solvent (PAN-CSA (m-cresol)) respresenting the most delocalized material, a negative ε{lunate}mw is measured indicating an intrinsic metallic state. The Drude model at low frequency is used to estimate a relatively small plasma frequency ωp {reversed tilde equals} 0.015 eV and an anomalously long scattering time τ {reversed tilde equals} 1.2 × 10-11 s. This τ implies the importance of phonon back scattering for the most delocalized electrons as expected for the open Fermi surface of a highly anisotropic metal. Depending on the crystallinity, there are two different charge localization regimes in PAN samples: uncoupled metallic islands and coupled "mesoscopic" metallic state. The three-dimensional nature of metallic state is demonstrated by the correlation of low temperature dielectric response with the parallel and perpendicular crystalline domain lengths obtained from x-ray data. The charge localization to delocalization transition dependence on the polymer processing will be discussed. We present the temperature dependent nonmetal-metal transition for some preparations of PAN-CSA (m-cresol). The intrinsic conductivity of metallic PAN is estimated to be ∼ 107 S/cm.
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M3 - Article
AN - SCOPUS:0029271605
VL - 69
SP - 251
EP - 254
JO - Synthetic Metals
JF - Synthetic Metals
SN - 0379-6779
IS - 1-3
ER -