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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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Journal ArticleDOI
TL;DR: In this paper, the electrical resistivity of FeCI3-doped polyvinylidene fluoride (PVDF) films, over the doping mass fraction range 0 ~< w ~< 0.40, have been measured.
Abstract: Infrared (350-4000 cm -1) and optical (1.1 5 x 1 04 - 2.95 x 1 04 cm -1) spectra, differential thermal analysis (DTA) and d.c. electrical resistivity of FeCI3- doped polyvinylidene fluoride (PVDF) films, over the doping mass fraction range 0 ~< w ~< 0.40, have been measured. The i.r. spectra provided evidence of: (a) the presence of both ~ and y phases in the undoped, and a y phase in the doped PVDF films; (b) a head-to-head content of 20%; and (c) a different doping mode beyond a 0.25 doping level. The optical spectra resulted in two induced energy bands, and a probable interband electronic transition, due to doping. Dipole relaxation and premelting endothermic peaks were identified by DTA. Electrical conduction is thought to proceed by interpolaron hopping among the polaron and bipolaron states induced by doping. The hopping distance, R o, is calculated according to the Kuivalainen model. A numerical equation is adopted to formulate the dependence of R o on doping level and temperature. It is found that Ro < CC separation length. This implies that, in doped PVDF, charge carrier hopping is not an intrachain process.

26 citations

Journal ArticleDOI
TL;DR: The formation of polarons in the presence of oxygen vacancies at the rutile TiO2 surfaces is a widely studied topic due to its importance in complex surface reactions as mentioned in this paper.
Abstract: The formation of polarons in the presence of oxygen vacancies at the rutile TiO2 surfaces is a widely studied topic due to its importance in complex surface reactions. In this paper, we have studied polaron formation both near and infinitely far away from the oxygen vacancy on the (110) rutile TiO2 surface by ab initio density functional theory and screened hybrid functionals. We conclude that a polaron prefers to stay near the oxygen vacancy due to electrostatic attraction between the positively charged oxygen vacancy and polaron. Although two polarons introduced by an oxygen vacancy repel each other, the oxygen vacancy effectively binds two polarons, forming a bipolaron. Moreover, our calculated vacancy formation energies elucidate the conditions under which the polarons are likely to be formed.

26 citations

Journal ArticleDOI
TL;DR: In this article, the thermodynamic properties of a three-dimensional Bose-condensate of translation-invariant bipolarons (TI-bipolarons) were investigated.
Abstract: Consideration is given to thermodynamical properties of a three-dimensional Bose-condensate of translation-invariant bipolarons (TI-bipolarons). The critical temperature of transition, energy, heat capacity and the transition heat of TI-bipolaron gas are calculated. The results obtained are used to explain experiments on high-temperature superconductors.

26 citations

Journal ArticleDOI
TL;DR: In this paper, a slightly doped spin gap state in double-chain system was studied in terms of Abelian bosonization method and it was shown that the spin gap formation in terms with the interchain exchange coupling J ⊥ persists only when the two chains are doped with equal number of carriers.

26 citations

Journal ArticleDOI
TL;DR: In this article, a theory of bipolaron states in quantum wires with a parabolic potential well is developed applying the Feynman variational principle, and the basic parameters of the bipolaron ground state (the binding energy, the number of phonons in the bipolarons in a cloud, the effective mass, and bipolaron radius) are studied as a function of sizes of the potential well.
Abstract: A theory of bipolaron states in quantum wires with a parabolic potential well is developed applying the Feynman variational principle. The basic parameters of the bipolaron ground state (the binding energy, the number of phonons in the bipolaron cloud, the effective mass, and the bipolaron radius) are studied as a function of sizes of the potential well. Two cases are considered in detail: a cylindrical quantum wire and a planar quantum wire. Analytical expressions for the bipolaron parameters are obtained at large and small sizes of the quantum well. It is shown that at $R\ensuremath{\gg}1$ [where $R$ means the radius (half width) of a cylindrical (planar) quantum wire, expressed in Feynman units], the influence of confinement on the bipolaron binding energy is described by the function $\ensuremath{\sim}{1/R}^{2}$ for both cases, while at small sizes this influence is different in each case. In quantum wires, the bipolaron binding energy $W(R)$ increases logarithmically with decreasing radius. The shapes and the sizes of a nanostructure, which are favorable for observation of stable bipolaron states, are determined.

26 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202316
202229
202127
202023
201920
201833