Thermally stimulated current in low-density polyethylene/MgO nanocomposite. on the mechanism of its superior dielectric properties

Kazuyuki Ishimoto, Toshikatsu Tanaka, Yoshimichi Ohki, Yoitsu Sekiguchi, Yoshinao Murata

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Polymer nanocomposites are attracting attention as emerging insulating materials. We measured the thermally stimulated depolarization current (TSDC) in low-density polyethylene (LDPE)/MgO nanocomposites while varying measuring such parameters as the temperature increase rate and the intensity of the applied electric field. A TSDC peak that spreads over a wide temperature range from 0 °C to 60 °C was observed in all samples. As the amount of MgO nanofiller increases, the TSDC peak height decreases. Furthermore, by adopting a partial heating method, the wide TSDC peak was resolved into several component peaks. Among them, the peak at about 12 °C was found not to appear in the base LDPE. Analysis of its initial rising portion indicated that the 12 °C peak had a fairly large energy depth of about 2 eV. These results indicate that charge carriers tend to be captured more strongly after the addition of MgO nanofillers. If these captured charge carriers induce homocharge layers in the vicinity of the electrodes, further space charge formation would be suppressed. This seems to explain the fact that the amount of space charge is smaller in nanocomposites with a proper addition of MgO than in the base LDPE.

Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalElectrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)
Issue number3
Publication statusPublished - 2011 Aug 1



  • insulating material
  • low-density polyethylene
  • polymer nanocomposite
  • thermally stimulated current

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

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