Structure and homogeneity ranges of the REAuZn series

The intermetallic compounds REAuZn (RE = Y, La, Pr, Nd, Sm, Gd–Tm, Lu) were synthesized from the elements in sealed tantalum ampoules in an induction furnace. They were characterized on the basis of powder and single crystal X-ray diffraction. Seven crystal structures have been refined from diffractometer data. The compounds with RE = Y, Dy–Tm, Lu crystallize with the hexagonal ZrNiAl type structure, space group P 6 ¯ 2m, while those with the larger rare earth elements La, Pr, Nd, Sm, Gd, and Tb adopt the orthorhombic TiNiSi type, space group Pnma. No temperature driven dimorphism has been observed for TbAuZn and DyAuZn. The structure refinements indicate small homogeneity ranges REAu1±xZn1±x with a pronounced tendency for a higher gold content.