Crystal structure and magnetic properties of the ternary rare earth metal-rich transition metallides RE 14 T 3Al3 (RE = Y, Gd–Tm, Lu; T = Co, Ni)

Abstract

Abstract The rare earth metal-rich RE 14 T 3Al3 series (RE=Y, Gd–Tm, Lu; T=Co, Ni) have been prepared by arc-melting the rare earth metals with appropriate amounts of TAl precursors. All compounds crystallize in the tetragonal crystal system with space group P42/nmc in the Gd14Co3In2.7-type structure. Two structures (Y14Co2.78(1)Al3.22(1): a=952.99(4), c=2292.98(10) pm, wR2=0.0423, 2225 F 2 values, 63 variables; Y14Ni3.07(2)Al2.93(2): a=955.06(5), c=2298.77(10) pm, wR2=0.0416, 2225 F 2 values, 63 variables) have been refined from single-crystal data, indicating T/Al mixing on one crystallographic site. The lattice parameters of all members have been refined from powder X-ray diffraction experiments. The Y and Lu containing compounds for T=Co and Ni exhibit Pauli paramagnetic behavior, indicating that the Co and Ni atoms exhibit no localized magnetic moment in line with a filled 3d band. The other compounds show paramagnetism, in line with the rare earth atoms in the trivalent oxidation state. Detailed magnetic investigations, however, were impossible due to the presence of e.g. RE 3 T trace impurities.