Features of Electroconductivity of γ-Irradiated Composites in Heating-Cooling Conditions

Nabi Shamshad Aliyev

doi:10.11648/j.ajpa.20150302.11

Abstract

It has been studied the behavior of temperature dependence of volume electroconductivity σ on direct current (DC) of composite medium of high-density polyethylene/α-Fe2O3 in the field of T=20-1350C within heating-cooling conditions before and after γ-irradiation at dose up to 500kGy. At lgσ(T) dependence of unirradiated composites while heating at low and high temperatures besides linear sections, it is observed the region of sharp decrease at 50-800C, associated with dipole orientation processes of adsorbed water molecules. At lgσ(T) dependence of composite samples irradiated at D=100kGy there is not any region of sharp decrease σ. It is shown that after γ-irradiation by dose D=500kGy the second maximum appears on the curve of forward trace of the composite HDPE+ 10%α-Fe2O3 at T=800C, which can be the result of change in the state of quasi-Fermi level. Behavior of lgσ(T) function at heating-cooling is explained by the “asymmetry” effect of electrically active defects. It is shown that the increase in volume conductivity after γ-irradiation is weakly expressed.

Highlights

The widespread use of polymer dielectrics and electroactive polymer composites (EAPC) with micro- and nano-size inorganic fillers as high-voltage electrical insulating materials in nuclear power plants and reactors, in cable technology [1,2,3], as well as electroactive elements in appliances and modern electronics devices [4,5,6,7], including the power supply systems of satellites and spacecraft, in which there is always nuclear radiation, is caused by a number of unusual and perspective properties in the applied relation
In our previous work [8], we reported the results of the experimental study of electrophysical properties of the composite system of high density polyethylene HDPE/αFe2O3
The results of studies of concentration, temperature and dose dependences of the electroconductivity on direct current of HDPE samples and composites of HDPE+α-Fe2O3 are shown in figure 1-3

Summary

Introduction

The widespread use of polymer dielectrics and electroactive polymer composites (EAPC) with micro- and nano-size inorganic (ferroelectric piezo- and pyroelectric ceramic materials, semiconductors, metal oxides, etc.) fillers as high-voltage electrical insulating materials in nuclear power plants and reactors, in cable technology [1,2,3], as well as electroactive elements (thin-film transistors, organic photocells, light-emitting diodes, touch panels, solar cells, random access memories and copiers, etc.) in appliances and modern electronics devices [4,5,6,7], including the power supply systems of satellites and spacecraft, in which there is always nuclear radiation, is caused by a number of unusual and perspective properties in the applied relation. Active studies are conducted, dedicated to the obtain and electroconductivity of EAPC They have lower conductivity compared to metals and are less stable, especially under the influence of ionizing radiation, temperature and other environmental factors have a major influence on the functional characteristics of the composites. These defects significantly limit their practical application. There is no theory that allows from a single physical concepts to describe the features of the electrical properties of heterogeneous materials in a wide temperature and frequency ranges In this regard, currently preference is given to experimental methods of studying features of interface and electrical characteristics of composite materials

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