Ternary rare earth-rich nickel cadmium compounds RE₁₄Ni₃Cd₃ (RE = Dy–Tm, Lu).

The rare earth-rich intermetallic cadmium compounds RE14Ni3Cd3 (RE = Dy–Tm, Lu) were synthesized by induction melting of the elements in sealed tantalum ampoules, followed by annealing in sealed quartz tubes in muffle furnaces. The polycrystalline samples were characterized by powder X-ray diffraction, confirming isotypism with Gd14Co3In2.7, space group P42/nmc. The structures of the holmium and lutetium compound were refined from single-crystal X-ray diffractometer data: a = 945.03(3), c = 2,275.64(7) pm, wR2 = 0.0316, 2800 F2 values, 64 variables for Ho14Ni3.70(1)Cd2.27(1) and a = 929.79(3), c = 2,237.53(6) pm, wR2 = 0.0537, 1315 F2 values, 63 variables for Lu14Ni3.69(3)Cd2.31. The striking structural feature of these cadmium phases is the formation of small defects on one 8g nickel site and Cd/Ni mixing on the Wyckoff position 4c. The complete RE14Ni3Cd3 structures can be described by a condensation of tricapped trigonal prisms around the nickel and icosahedra around the cadmium atoms. Temperature dependent magnetic susceptibility studies have revealed Curie-Weiss paramagnetism for Ho14Ni3Cd3, Er14Ni3Cd3 and Tm14Ni3Cd3 with antiferromagnetic transitions in the low-temperature regime (TN = 13.1(1), 8.6(1) and 3.6(1) K for RE = Ho, Er and Tm, respectively). [ABSTRACT FROM AUTHOR]