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Title: An effect of the electrode material on space charge relaxation in ferroelectric copolymers of vinylidene fluoride

Processes of relaxation of space charges formed by impurities carriers in isotropic films of vinylidene fluoride and tetrafluoroethylene copolymers of the composition 71/29 and 94/6 were studied. Al and Au symmetric electrodes deposited by evaporation in vacuum have been used. In the case of Al electrodes at temperatures above 100 °C, giant low frequency dielectric dispersion was observed, while it is absent in films with Au electrodes. Causes of this phenomenon were studied by the X-ray photoelectron spectroscopy. It was shown that at Al deposition, new functional groups, such as Al-C, Al-F, and Al{sub 2}O{sub 3}, which are not characteristic of the copolymer film surface, formed. They were supposed to be traps for impurity carriers and because of this the electrode became partially blocked. This led to appearance of the giant electrode polarization on the metal-polymer boundary, which did not take place in the case of Au electrodes. Parameters of the Au4f line for the copolymer with different contents of fluorine atoms in the chain were analyzed. An increase in the number of these atoms was shown to result in the line shift to higher energies. This phenomenon was associated with an increase in the shift of the electron density frommore » Au atoms to the F ones which has a high affinity to electrons.« less
Authors:
; ; ; ;  [1] ;  [2] ;  [3] ; ;  [4]
  1. State Research Center of the Russian Federation Karpov Institute of Physical Chemistry, Vorontsovo Pole 10, Moscow 103064 (Russian Federation)
  2. M.V. Lomonosov Moscow State University, Faculty of Physics, Leninskie Gory, Moscow 119991 (Russian Federation)
  3. Moscow State Pedagogical University, 1/1 M. Pirogovskaya Str., Moscow 119991 (Russian Federation)
  4. National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe Highway, 31, Moscow 115409 (Russian Federation)
Publication Date:
OSTI Identifier:
22493093
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 24; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AFFINITY; ALUMINIUM; ALUMINIUM OXIDES; COPOLYMERS; DEPOSITION; ELECTRODES; ELECTRON DENSITY; FERROELECTRIC MATERIALS; FLUORIDES; FLUORINE; GOLD; IMPURITIES; POLARIZATION; RELAXATION; SPACE CHARGE; SURFACES; THIN FILMS; X-RAY PHOTOELECTRON SPECTROSCOPY