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International Journal of Polymer Science
Volume 2009, Article ID 830270, 10 pages
http://dx.doi.org/10.1155/2009/830270
Research Article

Electrical Switching in Thin Films of Nandi Flame Seed Cuticles

1Physics Department, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya
2Institute of Experimental Physics 1, University of Leipzig, 04103 Leipzig, Germany

Received 2 October 2008; Revised 13 January 2009; Accepted 19 January 2009

Academic Editor: Patric Jannasch

Copyright © 2009 Wycliffe K. Kipnusu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Current-voltage ( 𝐼 - 𝑉 ) characteristics of Nandi flame seed cuticles (NFSCs) have been studied as a function of irradiation, annealing, and poling temperature. The cuticles showed memory and threshold switching. Threshold voltage 𝑉 t h was about 5 V which is almost five times higher than 𝑉 t h observed in synthetic polymers. The threshold voltage 𝑉 t h increased to 6–8 V after irradiation and annealing depending on the duration of annealing or irradiation. After switching, conductivity increased by an order of 1 0 2 . In reverse bias, increase of current was observed and the memory hysteresis loop was at higher conductivity than at the time of switching. Switching effect was minimized at a poling temperature of 370 K. Formation of semiquinones and quinoid radicals from phenolic compounds may have contributed to electrical switching and hysteresis effect.