CRYSTAL-STRUCTURE AND MAGNETIC-PROPERTIES OF THE OFF-STOICHIOMETRIC COMPOUNDS CENI3CU3 AND CENI4CU2

The crystallographic properties of the compounds CeNi3Cu3 and CeNi4Cu2 have been investigated by time-of-flight neutron diffraction. A Rietv eld profile refinement of the data shows that these compounds crystall ize in the hexagonal TbCu7-type structure and that Ni atoms have a gre ater preference as compared with Cu atoms for occupying the 2e dumb-be ll site. A site preference of Cu atoms for the 2e sites is observed. M agnetic measurements made on these compounds show that the trivalent c haracter of the Ce atoms increases with Cu concentration.