Eu TZn ( T=Pd, Pt, Au) with TiNiSi-type structure—Magnetic properties and 151Eu Mössbauer spectroscopy (original) (raw)

The europium compounds EuTZn (T ¼ Pd, Pt, Au) were synthesized from the elements in sealed tantalum tubes in an induction furnace. These intermetallics crystallize with the orthorhombic TiNiSi-type structure, space group Pnma. The structures were investigated by X-ray diffraction on powders and single crystals: a ¼ 732.3(2), b ¼ 448.5(2), c ¼ 787.7(2) pm, R 1 /wR 2 ¼ 0.0400/0.0594, 565 F 2 values for EuPdZn, a ¼ 727.8(3), b ¼ 443.7(1), c ¼ 781.7(3) pm, R 1 /wR 2 ¼ 0.0605/0.0866, 573 F 2 values for EuPtZn, and a ¼ 747.4(2), b ¼ 465.8(2), c ¼ 789.1(4) pm, R 1 /wR 2 ¼ 0.0351/0.0590, 658 F 2 values for EuAuZn, with 20 variables per refinement. Together the T and zinc atoms build up three-dimensional [TZn] networks with short T-Zn distances. The EuTZn compounds show Curie-Weiss behavior in the temperature range from 75 to 300 K with m eff ¼ 7.97(1), 7.70(1), and 7.94(1) m B /Eu atom and y P ¼ 18.6(1), 34.9(1), and 55.5(1) K for T ¼ Pd, Pt, and Au, respectively, indicating divalent europium. Antiferromagntic ordering was detected at 15.1(3) K for EuPdZn and canted ferromagnetic ordering at 21.2(3) and 51.1(3) K for EuPtZn and EuAuZn. 151 Eu Mössbauer spectroscopic measurements confirm the divalent nature of the europium atoms by isomer shift values ranging from À8.22(8) (EuPtZn) to À9.23(2) mm/s (EuAuZn). At 4.2 K full magnetic hyperfine field splitting is observed in all three compounds due to magnetic ordering of the europium magnetic moments.