RNi_9In_2 (R= Pr, Nd, Eu) compounds and their hydrides

摘要

RNi_9In_2 and their hydrides crystallize in the YNi_9In_2 structure type. Low pressure hydrogenation leads to absorption of 1.5-3.4 H/f.u. RNi_9In_2 (R= Pr, Nd) as well as PrNi_9In_2H_(1.7) and NdNi_9In_2H_(1.5) exhibit Curie-Weiss behaviour and lack of magnetic ordering down to T = 2 K. EuNi_9In_2 reveals ferromagnetism below approximately 40 K, which may be due to a secondary phase. Its hydride is Pauli paramagnet, indicating the Eu~(3+) state.