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Author Martin, James E. ♦ Heaney, Michael B.
Sponsorship (US)
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Publisher The American Physical Society
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ CARBON BLACK ♦ ELECTRIC FIELDS ♦ FLUCTUATIONS ♦ INSTABILITY ♦ MICROSTRUCTURE ♦ POLYETHYLENES ♦ RESISTORS ♦ THERMISTORS
Abstract Composites of carbon black particles in polyethylene exhibit an unusually rapid increase in resistivity as the applied electric field is increased, making this material commercially useful as current-limiting thermistors, also known as automatically resettable fuses. In this application the composite is in series with the circuit it is protecting: at low applied voltages the circuit is the load, but at high applied voltages the composite becomes the load, limiting the current to the circuit. We present a simple model of this behavior in terms of a network of nonlinear resistors. Each resistor has a resistance that depends explicitly and reversibly on its instantaneous power dissipation. This model predicts that in the soft fusing, or current-limiting, regime, where the current through the composite decreases with increasing voltage, a platelike dissipation instability develops normal to the applied field, in agreement with experimental observations, which is solely due to fluctuations in the microstructure.
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 2000-10-01
Publisher Place United States
Journal Physical Review B
Volume Number 62
Issue Number 14


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