MAGNETIC-STRUCTURES OF RARE-EARTHS R IN RCOC2 AND RNIC2 COMPOUNDS

A comparative survey is given on the variety of magnetic structures of the series of RCoC2 and RNiC2 with R = Pr, Nd, Tb, Dy, Ho, Er and Tm, which have been analysed by neutron diffraction. Rare earth structure relevant features are summarized. All compounds, except those with Pr , order magnetically at low temperatures. Magnetic order is confined t o the rare earths; Co and Ni sites remain non-magnetic. RCoC2 become f erromagnets; RNiC2 order antiferromagnetically in different spin confi gurations. The type of order and R dependent moment configurations are explained by RKKY exchange and additional crystal field interactions.