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

Vollständiger Abstract

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Abstract The rare earth metal-rich RE 14 T 3 Al 3 series ( RE =Y, Gd–Tm, Lu; T =Co, Ni) have been prepared by arc-melting the rare earth metals with appropriate amounts of T Al precursors. All compounds crystallize in the tetragonal crystal system with space group P 4 2 / nmc in the Gd 14 Co 3 In 2.7 -type structure. Two structures (Y 14 Co 2.78(1) Al 3.22(1) : a =952.99(4), c =2292.98(10) pm, wR 2=0.0423, 2225 F 2 values, 63 variables; Y 14 Ni 3.07(2) Al 2.93(2) : a =955.06(5), c =2298.77(10) pm, wR 2=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 3 d 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.