First- and second-order magnetic phase transitions in terbium and dysprosium

Abstract
High-resolution capacitance dilatometric measurements on the a, b and c axes of terbium and dysprosium indicate that, to a resolution of 1*10-6, the Neel transitions of both methods are second order. This is both in contrast to the prediction of Barak and Walker (1982), and also in contrast to the case of holmium, which has a first-order Neel transition.