Abstract
The temperature dependence of the conductivity σ in the low-dimensional material, NiPcI (Pc = phthalocyanine), is investigated using a transport theory for noninteracting electrons in a tight-binding band scattered by one- and two-phonon processes. The lattice motions found to be the dominant sources of resistivity along the chain are the longitudinal stretch and the interplanar twist (libron), with the former being a first-order scattering process (σ1p ∝ l/T) and the latter a second-order mechanism (σ2l ∝ 1/T2). The resulting conductivity has a room-temperature value of ∼400 Ω-1 cm-1 which increases to almost 4000 Ω-1 cm -1 at 50 K, with an overall temperature dependence of σ∼ T-1.4, in good agreement with experiment. It is found that at low temperature, one-phonon scattering is most important, while at room temperature one-phonon and two-libron scattering contribute nearly equally to the resistivity. The accuracy of the bandwidths and of the electron/phonon coupling constants, calculated using first-principles electronic structure methods, shows the value of these techniques for studying conduction in "molecular metals", while the good agreement of our calculated resistivity plots with those measured experimentally both supports the straightforward narrow-band picture used for the conduction process, and provides valuable insights into the design of optimal molecular metals of this class.
| Original language | English |
|---|---|
| Pages (from-to) | 5277-5285 |
| Number of pages | 9 |
| Journal | Journal of Chemical Physics |
| Volume | 83 |
| Issue number | 10 |
| Publication status | Published - 1985 |
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ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
Cite this
Conductivity mechanisms in phthalocyanine-based "molecular metals" : Calculation of the temperature-dependent resistivity. / Hale, Paul D.; Ratner, Mark A.
In: Journal of Chemical Physics, Vol. 83, No. 10, 1985, p. 5277-5285.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Conductivity mechanisms in phthalocyanine-based "molecular metals"
T2 - Calculation of the temperature-dependent resistivity
AU - Hale, Paul D.
AU - Ratner, Mark A
PY - 1985
Y1 - 1985
N2 - The temperature dependence of the conductivity σ in the low-dimensional material, NiPcI (Pc = phthalocyanine), is investigated using a transport theory for noninteracting electrons in a tight-binding band scattered by one- and two-phonon processes. The lattice motions found to be the dominant sources of resistivity along the chain are the longitudinal stretch and the interplanar twist (libron), with the former being a first-order scattering process (σ1p ∝ l/T) and the latter a second-order mechanism (σ2l ∝ 1/T2). The resulting conductivity has a room-temperature value of ∼400 Ω-1 cm-1 which increases to almost 4000 Ω-1 cm -1 at 50 K, with an overall temperature dependence of σ∼ T-1.4, in good agreement with experiment. It is found that at low temperature, one-phonon scattering is most important, while at room temperature one-phonon and two-libron scattering contribute nearly equally to the resistivity. The accuracy of the bandwidths and of the electron/phonon coupling constants, calculated using first-principles electronic structure methods, shows the value of these techniques for studying conduction in "molecular metals", while the good agreement of our calculated resistivity plots with those measured experimentally both supports the straightforward narrow-band picture used for the conduction process, and provides valuable insights into the design of optimal molecular metals of this class.
AB - The temperature dependence of the conductivity σ in the low-dimensional material, NiPcI (Pc = phthalocyanine), is investigated using a transport theory for noninteracting electrons in a tight-binding band scattered by one- and two-phonon processes. The lattice motions found to be the dominant sources of resistivity along the chain are the longitudinal stretch and the interplanar twist (libron), with the former being a first-order scattering process (σ1p ∝ l/T) and the latter a second-order mechanism (σ2l ∝ 1/T2). The resulting conductivity has a room-temperature value of ∼400 Ω-1 cm-1 which increases to almost 4000 Ω-1 cm -1 at 50 K, with an overall temperature dependence of σ∼ T-1.4, in good agreement with experiment. It is found that at low temperature, one-phonon scattering is most important, while at room temperature one-phonon and two-libron scattering contribute nearly equally to the resistivity. The accuracy of the bandwidths and of the electron/phonon coupling constants, calculated using first-principles electronic structure methods, shows the value of these techniques for studying conduction in "molecular metals", while the good agreement of our calculated resistivity plots with those measured experimentally both supports the straightforward narrow-band picture used for the conduction process, and provides valuable insights into the design of optimal molecular metals of this class.
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M3 - Article
VL - 83
SP - 5277
EP - 5285
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 10
ER -