Anomaly in the magnetocaloric effect in the intermetallic compound DYAl2

It is well known that the intermetallic compound DyAl2 is ferromagnetic and exhibits a change in the easy direction of magnetization from [100] to [111], for a critical applied magnetic field in the [111] direction. Using a simple model which includes the crystalline electric field and the exchange interaction we have theoretically investigated its magnetic entropy along the three main crystallographic directions. An anomalous behavior was theoretically predicted to exist in the magnetic entropy, which consists in the increase of entropy when the magnetic field is applied in the [111] direction, Comparisons between the theoretically predicted anomaly in DyAl2 with the recent discovery of a magnetic anomaly in PrNi5 are also presented.