Structure Refinement and Magnetic Properties of Ce₂RuAl₃ and a Group-Subgroup Scheme for Ce₅Ru₃Al₂

Abstract

The hexagonal Laves phase Ce 2 RuAl 3 (≡ CeRu 0.5 Al 1.5 ) was synthesized by high-frequencemelting of the elements in a sealed tantalum tube and subsequent annealing. The structure was refined from single-crystal X-ray diffraction data: MgZn 2 type, P6 3 /mmc, Z = 2, a = 565.38 (9)

Laves phases: superstructures induced by coloring and distortions

“…For this, one has to differentiate between fully ordered compounds and those that exhibit solid solutions with mixing of atoms onto the 2a and 6h site. While some compounds have been reported to adapt the Mg 2 Cu 3 Si type structure, others have been assigned to this structure type despite the fact that small amounts of mixing have been determined by single crystal X-ray diffraction (e. g. Ce 2 RuAl 3 [85] ). Despite the discussion about the prototype, interesting aspects can be observed from the reported compounds.…”

Lead flux crystal growth of Ce2Ru12P7

“…Atom designations are given in the lower right part. Thus, Ce 2 Ru 12 P 7 does not belong to the family of ceriumruthenium intermetallics with drastically shortened Ce-Ru distances [10,11]. The polyanionic [Ru 12 P 7 ] network in Ce 2 Ru 12 P 7 shows shorter Ru-Ru (266-302 pm) and Ru-P (222-277 pm) distances, indicating substantial Ru-Ru and Ru-P bonding, the characteristic structural motif of metalrich phosphides [1,5].…”

“…In the course of our systematic search for Ce x Ru y X z (X = element of 3 rd , 4 th , or 5 th main group, Mg, Zn, Cd) compounds with short Ce-Ru distances and with intermediate cerium valence [10,11] we became interested in metalrich cerium ruthenium phosphides. So far, the system Ce-Ru-P is characterized by the phosphides CeRu 2 P 2 [12], CeRu 4 P 12 [13,14], Ce 5 Ru 19 P 12 [15], and Ce 6 Ru 20 P 13 [16].…”

On the RE2TiAl3 (RE = Y, Gd–Tm, Lu) Series—The First Aluminum Representatives of the Rhombohedral Mg2Ni3Si Type Structure

“…Solids 2023, 4 167 for example, allows for an ordering on the two crystallographic Zn sites of the hexagonal MgZn 2 -type structure. Besides the prototype, aluminum compounds (e.g., Ce 2 RuAl 3 [13], the RE 2 TAl 3 series with RE = Y, La-Nd, Sm, Gd-Lu and T = Ru, Rh, Ir [14], U 2 Cu 3 Al [15] or the solid solution Ti 2 Ni 1-x Al 3+x [16]) along with gallides (U 2 Fe 3 Ga [17], Eu 2 IrGa 3 [18], Nb 2 Cu 1 . 1 Ga 2 .…”