On new ternary equiatomic scandium transition metal aluminum compounds ScTAl with T = Cr, Ru, Ag, Re, Pt, and Au

Abstract

The new equiatomic scandium transition metal aluminides ScTAl for T = Cr, Ru, Ag, Re, Pt, and Au were obtained by arc-melting of the elements followed by subsequent annealing for crystal growth. The samples were studied by powder and single crystal X-ray diffraction. The structures of three compounds were refined from single crystal X-ray diffractometer data: ScCrAl, MgZn2 type, P63 /mmc, a = 525.77(3), c = 858.68(5) pm, R1 = 0.0188, wR2 = 0.0485, 204 F2 values, 13 variables, ScPtAl, TiNiSi type, Pnma, a = 642.83(4), b = 428.96(2), c = 754.54(5) pm, R1 = 0.0326, wR2 = 0.0458, 448 F2 values, 20 variables and ScAuAl, HfRhSn type, P6?2c, a = 722.88(4), c = 724.15(4) pm, R1 = 0.0316, wR2 = 0.0653, 512 F2 values, 18 variables. Phase pure samples of all compounds were furthermore investigated by magnetic susceptibility measurements, and Pauli-paramagnetism but no superconductivity was observed down to 2.1 K for all of them. The local structural features and disordering phenomena have been characterized by27 Al and45 Sc magic angle spinning (MAS) and static NMR spectroscopic investigations.