Specific heat of silver-gold alloys below 30 °K

The present measurements on six alloys cover the range 2.5-30 ^∘{}K and are combined with earlier data below 3 ^∘{}K on the same alloys for analysis. The anomalous maximum at about 8 ^∘{}K in the Debye temperature of gold slowly decreases in magnitude and moves to lower temperatures as silver is added to gold. The alloy specific heats are compared with those calculated using the Kopp-Neumann rule (i.e., mixtures of the pure metals) and show negative percentage deviations of similar form for all alloys with the magnitude depending on composition and reaching a maximum for the equiatomic alloy. The nuclear entropy observed in the alloys but not in the pure metals is discussed in the context of the third law of thermodynamics and computation of the thermodynamic functions.