Electrical resistivity studies on polycrystalline and epitaxially grown gold films

Abstract

Studies of the thickness dependence of the temperature coefficient of resistivity and the ratio of resistivity at 298°K to that at 78°K of gold films epitaxially grown on mica support the conclusion that the conduction electrons are nearly (˜80 %) specularly reflected from the surface. The data on annealed films are in excellent agreement with the theory of diffuse scattering at both room and liquid nitrogen temperatures. The mean free path required to fit the data is approximately the same as in bulk and its value is about 400 Å and 1400 Å at 298°K and 78°K respectively. Similar studies of gold films deposited on fine grained, amorphous and crystalline substrates of niobium oxide show no dependence of the results on the crystallinity of the substrate and the data are again in agreement with the diffuse scattering theory for a mean free path of about 280 Å . Annealing of gold films deposited on niobium oxide substrates decreases the resistivity more markedly than in the case of smooth mica although no unusual decrease, as is found in the case of bismuth oxide substrates, is observed.