Electrical properties of binary amorphous alloys

Amorphous films of Au-Si, Mg-Zn, and Pt-Sb have been prepared by getter sputtering at 77^∘{}K over a wide range of compositions while the corresponding liquids can be quenched in the amorphous state only in a narrow range of compositions close to that of the eutectic. Their electrical resistance was measured in the temperature range 4.2-300^∘{}K. The results are compared with those obtained on similar liquid alloys and liquid quenched glasses. The resistivity and its temperature dependence are interpreted in terms of three scattering mechanisms: (a) Ziman theory, (b) structural defects, and (c) formation of covalent bonds, all of which being present in films, but (b) and (c) may be absent in bulk glasses and liquids. These differences in scattering account for the differences in electrical conduction of the three amorphous forms. Susceptibility measurements on amorphous Au-Si films and liquid Au-Si suggest a similarity between the amorphous and the liquid states. The present study would also suggest that while the eutectic composition is a crucial factor in obtaining an amorphous phase by quenching a liquid, it is not an important parameter in either the deposition of amorphous films or the properties of the amorphous phase.