MAGNETIC-INTERACTIONS IN LAVES PHASES - HEAT-CAPACITY OF PRNI2, GDNI2AND ERNI2

Heat capacity measurements of the intermetallic compounds PrNi2, GdNi2 and ErNi2 have been performed from 2 to 300 K. Magnetic ordering is o bserved for the Gd and Er compounds at 75.3 and 6.5 K respectively. Pr Ni2 and ErNi2 both show Schottky contributions coming from low energy levels. The heat capacity has been calculated with a model that takes into account the energy splitting of the ground multiplet due to the c rystal electric field (CEF) and the exchange interaction in a molecula r field approximation. The crystal field and exchange parameters have been deduced from our results.