The heat capacity of β-cerium between 1.5 and 23 K

The heat capacity of single-phase β-cerium has been determined between 1.5 and 23 K with special emphasis on the shape of the antiferromagnetic ordering peak. It is concluded that separate ordering occurs at 12.45 and 13.7 K for the two types of site symmetry. The lower-temperature peak is thought to be associated with ordering of the cubic sites and the upper peak with the ordering of the hexagonal sites. An analysis of the various contributions to the heat capacity is made. The magnetic heat capacity between 1.5 and 2.3 K exhibits an exponential behavior, yielding an energy gap of 2.92 K, and between 3.5 and 6.5 K it exhibits a T³ behavior.