Electrical Resistance of Copper-Gold Alloys at Low Temperatures

The resistance of copper-gold alloys of composition 25, 37.5, 50, 62.5, and 75 atomic percent gold has been measured as a function of temperature from room temperature to 2°K in states slowly cooled and rapidly quenched from above the ordering temperatures. The room temperature resistivities agree with those previously obtained by Johanssen and Linde. The residual resistances are high in both the quenched and slowly-cooled states, but the ratio of residual resistance to the ice point resistance was found to be appreciably lower in the slowly-cooled states for the 25 and 50 atomic percent gold composition. The other compositions showed no such difference in the residual resistance ratio for the quenched and annealed states. Values of Debye temperature calculated by means of the Grüneisen function were found to be strongly temperature dependent, and no appreciable difference was found in the Debye temperatures of the quenched and slowly-cooled states. The Debye temperatures at 75°K were found to obey the equation: $\frac{1}{{{\theta }_{\mathrm{AB}}}^3}=\frac{x}{{{\theta }_A}^3}+\frac{\mathrm{}(1-x)\mathrm{}}{{{\theta }_B}^3}$. Hysteresis anomalies of the order of 1 percent were found in the neighborhood of 225°K.