V.M. Kornilov

On the high conductivity of nonconjugated polymers

The mechanism of charge transfer in a metal-electroactive polymer-metal structure has been experimentally studied near the threshold of the uniaxial-pressure-induced transition into a high-conductivity state in the polymer. The dynamics of the I-V curve is investigated as a function of the applied pressure. The data obtained are analyzed in terms of the model of injection currents using the concepts of possible scanning of a quasi-Fermi level near an injection level. Our estimates suggest that a narrow band made of deep trap states located near the Fermi level forms in the polymer film in the pretransition pressure range. In the immediate vicinity of the transition range, a narrow band of coherent charge transfer appears from these states; this band can be responsible for the high metal-type conductivity of thin polymer films, which has been repeatedly observed by many researchers.

Metal phase in electroactive polymer induced by uniaxial pressure

Abstract The paper considers a metal state induced by a weak uniaxial pressure in electroactive polymers —polyphthalidilidenarylenes. The comparison with polyanyline is performed.

Metal phase in electroactive polymer induced by traps ionization

Abstract The paper presents the insulator-metal transition in thin polymer films induced by the thermal ionization of traps. The thermostimulated currents and thermal excitations in the IR absorption spectrum and complex dielectric permittivity are investigated. The metal phase was shown to occur due to interaction of the nonequilibrium charge, appearing as a result of the traps ionization, with the polymer molecules.

New effects in electroactive polymers: new basics for sensors

Abstract Recently, new conjugated polymers of the poly(phthalidylidenarylene)s class have been synthesized. They consist of functional units sensitive to a number of external influences, such as temperature, pressure, electric field, pH-medium, etc. These influences cause an insulator-metal transition in the polymer film. As a result, the film resistance changes by 10–12 orders of magnitude. In addition, the films display electroluminescence. These phenomena open broad prospects for the application of these polymers in a variety of industrial products.

Study of Collective Electronic Effects Caused by Severe Plastic Deformation

The severe plastic deformation (SPD) of metals is known to modify their crystal structure. Particularly, the average size of the crystalline grains considerably decreases while the extent of crystal lattice distortion and amorphous phase both increase. Such a state is characterized as non-equilibrium one. When the metal is in this state, it undergoes a polymorphous transformation at temperatures below the melting point (most intensive at T ~ 0.4 Tmeit).

Metal-like state in undoped polymer films: techniques of inducing and properties

Summary form only given. An abnormally high sensitivity of the conductivity of thin polymer films to some external influences, such as uniaxial pressure, electric field, temperature, electron beam has been discovered. A common feature for all these phenomena is that they are shaped as the dielectric-metal phase transition which are initiated by external influences of the abnormally low values. The latter include uniaxial pressure, electric field, electron beam and temperature. The present paper discusses experimental results obtained during the investigations of the phenomena.