APd2Zn3 (A=Ca, Sr, Eu) with a CaCu5 superstructure

Abstract The intermetallic phases A Pd 2 Zn 3 ( A =Ca, Sr, Eu) were synthesized from the elements in sealed niobium ampules in an induction furnace. The phase purity of the samples was checked by powder X‐ray diffraction (Guinier technique). The structures were refined from single crystal X‐ray diffractometer data: YNi 2 Al 3 type (CaCu 5 superstructure), P 6/ mmm , a =936.97(4), c =420.75(2) pm, wR 2=0.0206, 259 F 2 values, 17 variables for CaPd 2 Zn 3 , a =953.63(6), c =425.38(3) pm, wR 2=0.0185, 230 F 2 values, 17 variables for SrPd 2 Zn 3 and a =948.20(7), c =423.20(3) pm, wR 2=0.0209, 228 F 2 values, 18 variables for EuPd 2.12(1) Zn 2.88(1) . The europium‐based crystal showed a small homogeneity range through Pd/Zn mixing. The striking structural motifs of the A Pd 2 Zn 3 phases are Kagome networks formed by the palladium and zinc atoms. The superstructure formation (discussed on the basis of a Bärnighausen tree) results from a different Pd/Zn coloring and a shift of one A position by c /2. The divalent character of europium in EuPd 2 Zn 3 was substantiated by magnetic susceptibility and 151 Eu Mössbauer spectroscopic measurements. EuPd 2 Zn 3 orders ferrimagnetically at T C =17.5(5) K. The magnetization behavior at 3 K (two‐step magnetization) confirms the existence of two crystallographically independent europium sites. The 151 Eu Mössbauer spectrum at 5 K shows full magnetic hyperfine field splitting ( δ =−8.99(4) mm s −1 and B Hf =27.7(1) T).