Analytical expressions of the electrical conductivity and the temperature coefficient of resistivity of two thin coaxial metallic wires

Assuming, that the sources of scattering act independently in the two thin coaxial metallic wires, and introducing the mean free path describing the Fuchs–Sondheimer effect, an apparent size effect is then defined.The aim of this paper is to show that the size effects in the thin coaxial metallic wires can be examined as well by using initially the theoretical formulations proposed in the case of a single wire and of the thin double-layer metal films. Simple analytical expressions of the electrical conductivity and the temperature coefficient of resistivity are therefore proposed.