Copyright © 1980 Hindawi Publishing Corporation. 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

A range of films of mixed composition, prepared by arc plasma spraying, has been investigated. Both free powder and powder in a plastic binder forming a rod have been used in the spray process. A variety of mixtures of insulators, metals and semiconductors has been examined and it is shown that resistivity/temperature curves for the specimens produced have in general two points of inflection, the temperatures of which vary with composition. This allows prediction of a composition giving low T.C.R. at room temperatures for any given metal/semiconductor combination. A qualitative theoretical model explaining this effect is presented. It has also been demonstrated that a conductor/insulator combination need not necessarily exhibit a sharp transition. This allows a broad range of resistance values to be obtained simply by varying composition.