Heat Capacity of PrNi₂, YNi₂ and Pseudobinary PrcLa1-cNi₂ System

Heat capacity data are presented for intermetallic compounds PrNi 2 , YNi 2 and the pseudobinary system Pr c La 1- c Ni 2 . The temperature range covered is 2 to 80 K. The magnetic heat capacity deduced under certain assumptions shows that in PrNi 2 the singlet \(₁\) is the ground level and that the first excited level lies about 60 K above the ground level. An excess contribution is found around 10 K. The excess heat capacity is understood if the excited level is assumed to have appreciable broadening due to the exchange interaction acting between Pr atoms.