The possibility of forming the gold–lead intermetallic compounds Au2Pb, AuPb2 and AuPb3 in tunnel structures using thin films of aluminum, aluminum oxide, lead, and finally gold is being studied. The room temperature diffusion of gold into lead films with thickness in the range 1000–3600 Å is found to be rapid, with indications of compound formation taking place within a few hours. Variation of the thickness ratio of the lead and gold films is used to preferentially form a given intermetallic. Each intermetallic is characterized by its transition temperature Tc, energy gap Δo, and by a unique phonon spectrum which is reflected in the derivatives of the tunneling characteristics.