Resistivity of the solid solutions (Co-Ni)Si2

Solid solutions of CoSi2 and NiSi2 were prepared from the solid-state reaction of thin films of Ni-Co alloys with their silicon substrates. The room-temperature resistivity of these silicide solid solutions does not increase parabolically, but (within the sensitivity of the measurements) varies linearly with composition. A model is proposed which explains the very weak alloy scattering on the basis that in these disilicides (a) the d bands are pushed below the Fermi level, (b) conduction occurs mostly via s electrons, and (c) there is no s-d scattering.