Physics of Organic Materials and Devices

Dielectric behavior of ternary composites of epoxy/BaTiO₃/(CuO or MgO)

A. Benhamouda^a1, J. M. Forniés-Marquina^a2, N. Bouzit^a1 and N. Bourouba^a1

Laboratoire d'Instrumentation Scientifique (LIS), Département d'Électronique, Faculté des Sciences de l'Ingénieur, Université Ferhat Abbas, 19000 Setif, Algeria

Departamento de Fisica Aplicada, Grupo de Electromagnetismo Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain

Abstract

The work we present in this article is an investigation of the optimal dielectric behaviour of a ternary composite based on a mixture of epoxy resin, titanates and oxides. Titanates are known by their capacity to provide high dielectric constant values that make their use very important in system of telecommunication, transmission microwaves, and in integrated circuit technology. A comparative study is established on two types of oxides added to titanates of either calcium, barium, or magnesium following different proportions. The protocol used to characterise different mixtures is the Time Domain Reflectometry (TDR). The acquired results show a good concordance between the experimental values of the ternary mixture dielectric constant and the theoretical models deduced from the Lichtenecker modified law. The copper oxide (CuO) is revealed to be more influential than the magnesium oxide (MgO) on the added titanate because of an insignificant dielectric behaviour that the latter presents. On the other hand, the linear behaviour of appeared with a CuO concentration round about 15% in a RE.BT.CuO mixture. For a fixed barium titanate fraction (27%) this linear evolution is located between the upper and the lower limits derivative from direct and inverse Wiener laws.

(Received July 1 2008)

(Revised December 2 2008)

(Accepted January 26 2009)

(Online publication April 1 2009)

PACS:

• 77.22.Ch – Permittivity;
• 77.22.Gm – Dielectric loss and relaxation

bouzitnacerdine@yahoo.fr