The specific heat of β- brass

The specific heat of β-brass as measured by Sykes (1935) and by Moser (1936) shows an anomalous rise beginning at 160° C a sharp maximum- a λ-point-is reached and the specific heat drops abruptly to low values, the whole drop taking place with in 7°. Moser states that this drop is steep but continuous. Both authors obtain a slope of 0·03 cal./degree2g. approximately by interpolating between their experimental values. The thermal expansion coefficient goes parallel with the specific heat and has a maximum of similar shape (Steinwehr and Schulze 1934). This phenomenon is explained as the transition of the Cu and Zn atoms from an ordered arrangement to disorder.