New members of the tetragonal RE14T3Al3 (RE=Sc, Y, Dy-Tm, Lu; T=Cu, Rh, Pd) series

摘要

The rare-earth metal-rich RE14T3Al3 series (RE=Y, Gd-Tm, Lu) was extended to the transition metals T=Cu, Rh, and Pd. All compounds have been prepared by arc-melting the rare-earth elements with appropriate amounts of TAl precursors. The compounds crystallize in the tetragonal Gd14Co3In2.7-type structure with space group P4(2)/nmc. Two structures (Y14Rh2.97(1)Al3.03(1): a=952.99(4) pm, c=2292.98(10) pm, wR2=0.0423, 2225 F-2 values, 63 variables; Y14Pd3.16(1)Al2.84(1): a=955.06(5) pm, 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 two crystallographic sites. The lattice parameters of all synthesized representatives have been refined from Guinier powder X-ray diffraction data. The Y and Lu containing compounds show Pauli paramagnetic behavior, indicating that the transition metal atoms have filled d bands and exhibit no localized magnetic moment. From the other compounds only Er14Pd3Al3 was obtained as an X-ray pure sample. It shows paramagnetism, in line with the rare-earth atoms in the trivalent oxidation state and antiferromagnetic ordering below T-N=8.0(1)K. Detailed magnetic investigations on the other members were impossible due to the presence of, e.g., RE3T trace impurities.