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Interplay of Hopping and Percolation in Organic Conducting Blends
Author(s) -
Fraysse J.,
Planès J.
Publication year - 2000
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(200003)218:1<273::aid-pssb273>3.0.co;2-s
Subject(s) - percolation threshold , exponent , condensed matter physics , materials science , percolation (cognitive psychology) , conductivity , electrical conductor , scaling , critical exponent , electrical resistivity and conductivity , percolation theory , power law , physics , phase transition , quantum mechanics , composite material , mathematics , philosophy , linguistics , geometry , statistics , neuroscience , biology
Electronic transport properties of organic conductive blends made of doped poly(aniline) and poly(methyl methacrylate) are studied as a function of the conductive phase fraction p and the temperature T . As p is varied, the scaling law of electrical percolation, σ ∝ ( p — p c ) t , is obeyed by the dc conductivity σ with a single value of p c = 0.07% for a wide range of temperatures. Conversely, the conductivity exponent t increases monotonically from 1.4 to 4.3 as T decreases. At constant p , the thermal dependence of σ is described by the superposition of a metallic part and a hopping part. In the hopping law, ln σ ∝ —( T 0 / T ) γ , the exponent is p dependent. Considering a wide and T dependent distribution of local conductances, we may explain the non‐canonical behavior of exponents t (continuous percolation model) and γ.