We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Solid solutions EuAu<sub>4</sub>Cd<sub>2−x</sub>Mg<sub>x</sub> with a remarkably stable ferromagnetic ground state.
- Authors
Reimann, Maximilian K.; Bönnighausen, Judith; Klenner, Steffen; Pöttgen, Rainer
- Abstract
Samples of the solid solutions EuAu4Cd2−xMgx were synthesized from the elements in sealed tantalum ampoules. The elements were reacted at a maximum temperature of 1273 K followed by slow cooling. For crystal growth, the polycrystalline samples were ground to powders, pressed to pellets and annealed again. All samples crystallize with the tetragonal YbAl4Mo2-type structure, space group I4/mmm. The solid solution extends up to x = 1 and the Cd/Mg substitution has only a minor influence on the lattice parameters. The samples have been characterized by powder X-ray diffraction and the structure of EuAu4Cd1.58(2)Mg0.42(2) was refined from single crystal X-ray diffractometer data: a = 715.46(14), c = 549.96(11) pm, wR2 = 0.0334, 180 F2 values and 11 variables. The striking crystal chemical motifs of the EuAu4Cd2−xMgx structures are Eu@Au12 and (Cd/Mg)@Au8(Cd/Mg)2 polyhedra and linear Cd/Mg chains in form of a tetragonal rod packing with distances of 275 pm for Cd/Mg–Cd/Mg. Temperature dependent magnetic susceptibility measurements of all samples from the solid solutions EuAu4Cd2−xMgx revealed Curie–Weiss behavior and stable divalent europium. All samples are ordered ferromagnetically around T = 16 K, and magnetization isotherms at 3 K classify these materials as soft ferromagnets. It is remarkable that the structural Cd/Mg disorder within the chains does not influence the ferromagnetic ground state. The divalent nature of europium in these intermetallics was exemplarily studied for the EuAu4Cd1.4Mg0.6 sample by 151Eu Mössbauer spectroscopy. At 6 K the isomer shift is −9.95(4) mm s−1 and one observes full magnetic hyperfine field splitting with Bhf = 27.1(1) T.
- Publication
Zeitschrift für Naturforschung B: A Journal of Chemical Sciences, 2020, Vol 75, Issue 6, p643
- ISSN
0932-0776
- Publication type
Article
- DOI
10.1515/znb-2020-0066