Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-14T17:15:49.216Z Has data issue: false hasContentIssue false
  • English
  • Français

Ionic Space Charge Relaxation and High Dielectric Permittivity in Polyethylene Oxide

Published online by Cambridge University Press:  10 February 2011

A. Wagner  and
H. Kliem
A. Wagner
Affiliation:
Institute of Electrical Engineering Physics, University of Saarland, D-66041 Saarbrucken, Germany
H. Kliem
Affiliation:
Institute of Electrical Engineering Physics, University of Saarland, D-66041 Saarbrucken, Germany
Get access

Abstract

Thin films (0.3μm to 11.2 μm) of Polyethylene Oxide (PEO) with molecular weights from 6 × 103 to 4 × 105 were prepared from aqueous solutions by a spin technique as AI-PEO-AI structures, or as AI-PEO-Si structures. Dielectric measurements (capacitance and loss angle) were carried out in a frequency range 3 mHz ≤ f ≤ 1 MHz in atmospheres of different relative humidity (0% r.h. to 75% r.h.) and at different temperatures (293 K to 323 K). The nominal dielectric permittivity exhibits a remarkable dependence on the sample thickness and the relative humidity. We find a true volume polarization in the high frequency range and a thermally activated relaxation process in the low frequency range, whose time constant is shifted towards high frequencies with increasing r.h.. It is considered that due to the absorbed dipolar water molecules chemical bonds within the sample are broken and quasi-free ions are generated. These ions move through the sample to the electrode interfaces and form an ionic space charge. We assume that at the PEO-Al interface an oxide layer is formed, which is impermeable for these ions. The transit times and the drift velocities of the ions are almost independent of the electric field strength in the low-field limit. Therefore we conclude that the movement of the ions can be described by a multiwell potential model, where the transition probability between neighbored wells is thermally activated.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 548: Symposia EE – Solid State Ionics V , 1998 , 353
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Gauthier, M., Armand, M., Muller, D. in Electroresponsive, Molecular and Polymeric Systems 1 pp. 41–95 Ed. Skotheim, T.A., New York: Dekker 1988 Google Scholar
2. Riande, E., J. Pol. Sci. 14 pp. 2231–2240 (1976)Google Scholar
3. Kliem, H., Trans. El. Ins. 24 pp. 185–197 (1989)Google Scholar
4. Homann, M., Kliem, H., Microel. J. 25 pp. 559–566, (1994)Google Scholar
5. Röhl, P., Siemens Forsch.- u. Entwickl.-Ber. Bd 14 pp. 104–103 (1985) Nr. 3, Springer 1985Google Scholar
6. Kliem, H., Schröder, K., and Bauhofer, W., CEIDP Ann. Rep. pp. 12–15 (1996)Google Scholar