Fabrication and study of the electrical properties of PbO/Fe based composite resistors

Abstract

Lead Oxide and Iron based composite resistors of constant diameter (0.6cm) and varying lengths ranging from 0.37 to 1.17cm were fabricated. The resistors were fabricated by the use of a moulder with the application of an average pressure of 1.5×106 Nm-2. The research is aimed at fabrication and study of the electrical properties of cermets resistor, with particular interest in electrical resistance as a function of Temperature Coefficient of Resistance, (TCR), length, varying composition and firing temperature. The electrical properties measured showed that the electrical resistance varied with iron content and also increased non - linearly with the length of the resistors. The peak firing temperature and firing time were found to have considerable effect on the resistance of the resistors. The resistance values fall with increasing firing temperature. All the resistors have negative TCRs with some of the resistors having TCR as low as -3579.4 ± 14.5 ppm/OC. These results are comparable with those of thermistors. Resistors of low resistance values were obtained and this largely depended on the composition of the materials used.

Keyword: Fabrication, Resistors, Lead oxide, TCR