A CONTRIBUTION TO CRYSTALLOCHEMISTRY OF TERNARY 1 1/2 RARE-EARTH INTERMETALLIC PHASES WITH TL, SB, RI AND PD/

The ternary alloys RXPd(2) where R is one of the rare earths and X is thallium or antimony or bismuth were studied for the stoichiometric ra tio 1:1:2. The structure of these alloys and their homogeneity fields were examined. All the alloys studied have the cubic structure cF16 Al Cu2Mn-type. For the series RTIPd(2) the compounds were obtained with t he following rare earths: Y, Sm, Gd, Dy, Ho and Er; for X = Sb with he avy rare earths (R = Gd, Dy, Ho, Er, Yb), and for X = Pi with R = Pr, Sm, Gd, Tb, Dy, Ho, Er, Yb. We have also studied a few ternary compoun ds with the stoichiometric ratio 1:1:1 in the series RBiPd which have the cubic structure cF12 MgAgAs-type. For the aforementioned compounds structural data are given and the role of atomic volume as a controll ing factor is discussed.