On the miscibility gap of Cu-Ni system

The existence of the miscibility gap in the Cu-Ni system has been an issue in both computational and experimental discussions for half a century. Here we propose a new miscibility gap in the Cu-Ni system measured in nano-layered films by Secondary Neutral Mass Spectrometry. The maximum of the symmetrical miscibility curve is around 780K at Cu50%Ni50%. This is the first experiment determining the miscibility from the measurement of the atomic fraction of Copper and Nickel in the whole composition range.