Class

Article

College

College of Science

Department

Physics Department

Faculty Mentor

JR Dennison

Presentation Type

Oral Presentation

Abstract

Temperature-dependent electrical conductivity measurements of polymers are compared to predictions by thermally assisted hopping conductivity, commonly used to model electron transport between defect sites in highly disordered insulating materials (HDIM). Constant voltage is applied across samples using a parallel plate geometry under vacuum, with the resulting current measured using a high resolution electrometer to calculate extreme low level conductivity. Conductivity of thin film PEEK (polyether ether ketone) and LDPE (low density polyethylene) samples was measured at temperatures ranging from 270 to 350 K to determine temperature influence on conductivity. Long time scales are needed for polymers to reach electrostatic equilibrium to isolate the different conduction mechanisms present in insulators from the temperature dependence under study. Results include determination of the rate of change in conductivity over change in temperature of the materials using two methods over narrow and wide temperature ranges, demonstrating the sensitive effect temperature has on the conductivity of HDIM.

Location

Room 154

Start Date

4-10-2019 9:00 AM

End Date

4-10-2019 10:15 AM

Share

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Apr 10th, 9:00 AM Apr 10th, 10:15 AM

Temperature-Dependent Conductivity of Highly Insulating Polymers

Room 154

Temperature-dependent electrical conductivity measurements of polymers are compared to predictions by thermally assisted hopping conductivity, commonly used to model electron transport between defect sites in highly disordered insulating materials (HDIM). Constant voltage is applied across samples using a parallel plate geometry under vacuum, with the resulting current measured using a high resolution electrometer to calculate extreme low level conductivity. Conductivity of thin film PEEK (polyether ether ketone) and LDPE (low density polyethylene) samples was measured at temperatures ranging from 270 to 350 K to determine temperature influence on conductivity. Long time scales are needed for polymers to reach electrostatic equilibrium to isolate the different conduction mechanisms present in insulators from the temperature dependence under study. Results include determination of the rate of change in conductivity over change in temperature of the materials using two methods over narrow and wide temperature ranges, demonstrating the sensitive effect temperature has on the conductivity of HDIM.