Hopping conduction bonding

Pavlenko, N.I. (2000). Proton hopping conductivity in quasi-one-dimensional hydrogen-bonded chains. Phys. Stat. Solidi B 218, 295-298. 

T. Odagaki and M. Lax [1980] AC Hopping Conductivity of a One-dimensional Bond-Percolation Model. Phys. Rev. Lett. 10, 847-850. 

Four peaks (a, P, y and 8) are assigned to the oxidised strnctnre, the aromatic form, the quinoid form, and the 2,3-bond structure, of polypyrrole, respectively. The half-width of peak y is a measure of electrical conductivity. Electrical conductivity measurements at room temperature and -23 °C show that the hopping conduction mechanism is the dominant one for polypyrrole. 

Nonstoichiometric compounds are mixed-valence compounds with nonintegral electron/atom ratios. Electronic properties of these compounds depend crucially on the nature and magnitude of nonstoichiometry. Electronic conduction in many such compounds occurs by hopping between the cations of different valencies (e.g. Pr " " and Pr" " in Pri2022)- Nonstoichiometry with a wide range of compositions is more common in oxides, sulphides, and related materials where the bonding is not completely ionic. In ionic nonstoichiometric compounds, structural rearrangements... 

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