Topic
Bipolaron
About: Bipolaron is a research topic. Over the lifetime, 1335 publications have been published within this topic receiving 29154 citations. The topic is also known as: bipolarons.
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TL;DR: A new interpretation of the spin-charge relation and of the so-called Curie and Pauli contributions to the susceptibility of disordered conducting polymers is derived.
Abstract: We emphasize the role of the dopant potential on the stability and magnetic properties of bipolarons in a conducting polymer. For this purpose the singlet and the triplet states of a bipolaron have been calculated within an adiabatic deformable continuum model including short-range Coulomb repulsions between electrons and attractions by the ionized dopants. We derive a new interpretation of the spin-charge relation and of the so-called Curie and Pauli contributions to the susceptibility of disordered conducting polymers.
44 citations
TL;DR: In this article, the main difficulties of superconductivity in high-Tc oxides and in doped fullerenes are analysed in the light of some experimental observations paying special attention to those in which pairs exist or are claimed to be observed above Tc.
Abstract: Theories describing superconductivity in high-Tc oxides and in doped fullerenes can be placed in four categories: Fermi-liquid (FL), BCS-like schemes and non-FL theories with electro-phonon or electronic mechanisms of pairing. The main difficulties are analysed in the light of some experimental observations paying special attention to those in which pairs exist or are claimed to be observed above Tc.
44 citations
TL;DR: The kinetics of anodic coupling to dimers of thiophene oligomers (n = 3, 6, 8, 8 and 10) were investigated by in situ conductivity and chronopotentiometry as mentioned in this paper.
43 citations
TL;DR: In this article, the use of polythiophene films as supporting matrix for Pt particles was reported, and the polymer film hosts were prepared using a strong acid aqueous solution, impregnated with Pt particles, and then tested for electrocatalytic properties for the oxygen reduction reaction (ORR).
Abstract: This work reports the use of polythiophene films as supporting matrix for Pt particles. The polymer film hosts were prepared using a strong acid aqueous solution, impregnated with Pt particles, and then tested for electrocatalytic properties for the oxygen reduction reaction (ORR). Cyclic voltammetry shows that the redox behavior of polythiophene in 12.5 M H 2 SO 4 presents a general feature equivalent to that of several other conducting polymers, especially polypyrrole. Features of the UV-visible spectra obtained during the redox process are consistent with the polaron/bipolaron model. Scanning electron microscopy measurements show that a very homogeneous film layer is obtained with the Pt deposited as very fine particles. Polarization measurements have shown that the ORR occurs through a mechanism involving four electrons with Tafel slopes of ca. 0.12 V dec -1 for potentials below 0.85 V vs. RHE (reference hydrogen electrode), in agreement with previous results for other types of dispersed Pt electrocatalysts.
43 citations
TL;DR: In this article, a modified model for bipolaron correlated barrier hopping (CBH) is proposed, since the usual bipolaron CBH model has been found to be inconsistent with experimental data for ac conductivity for chalcogenide glasses at high temperatures.
Abstract: In this study, a modified model for bipolaron correlated barrier hopping (CBH) is proposed, since the usual bipolaron CBH model has been found to be inconsistent with experimental data for ac conductivity for chalcogenide glasses at high temperatures. The present model is based on the existence of a focal point when the experimental data are extrapolated to high temperatures on the σ(ω)–1/T plot. The correct analysis must introduce the concept of the Meyer–Neldel rule in the expression of the relaxation time. The results of the present model are in quantitative agreement with reported ac conductivity measurements.
42 citations