Low temperature specific heats of α phase AgCd and AgPd alloys

Specific heat data between 1 and 4°K are presented on α phase AgCd and AgPd alloys. Dilute additions of either Cd or Pd produce a slow rise in the electronic specific heat, and the same is true of ternary alloys in which Cd and Pd are added simultaneously. This behaviour is in conflict with the rigid band model, and various possible reasons for this are discussed. A simple rigid band analysis of the data for the Pd-rich alloys suggests that there are about 0.48d holes per atom in pure Pd, whereas it is known from Fermi surface studies that the cor­rect number is 0.36. It is argued that the rigid band model is not correct for Pd alloys, and an alternative model is proposed based on a comparison of the specific heats with Mössbauer data.