The low temperature specific heats of some Laves phases containing neodymium

Specific heat measurements have been made between 0.2 and 4 K on NdNi 2 , NdAl 2 and NdCo 2 and also on LaAl 2 . Hyperfine contributions have been identified in the neodymium compounds, and the ionic moments deduced, giving 1.63 mu B , 2.39 mu B and 2.63 mu B respectively. These moments, the known Curie temperatures and paramagnetic susceptibilities, can all be interpreted in terms of a common model to represents crystal field and exchange effects. All three compounds have 'electronic' specific heats which are far larger than the electronic specific heat of LaAl 2 ( gamma =12.1 mJ mole -1 K -2 ).