Synthesis and structure of RE2RuMg2 (RE = Dy, Ho, Er, Tm, Lu) – i5 superstructures of the bcc packing

✍ Scribed by Kersting, Marcel (author);Niehaus, Oliver (author);Hoffmann, Rolf Dieter (author);Pöttgen, Rainer (author)

• Book ID: 121422667
• Publisher: Oldenbourg Wissenschaftsverlag
• Year: 2013
• Tongue: English
• Weight: 427 KB
• Volume: 228
• Category: Article
• ISSN: 2194-4946
• DOI: 10.1524/zkri.2013.1692

✦ Synopsis

The isotypic intermetallic compounds RE 2 RuMg 2 (RE ¼ Dy, Ho, Er, Tm, Lu) were synthesized from the elements in sealed niobium tubes in a muffle furnace with different annealing sequences. The polycrystalline samples were characterized through Guinier powder patterns. The structure of Er 2 RuMg 2 was refined on the basis of single-crystal X-ray diffractometer data: ordered Os 2 Al 3 type, I4/mmm, a ¼ 338.44(5), c ¼ 2029.4(4) pm, wR2 ¼ 0.0237, 234F 2 values, and 10 variables. The Er 2 RuMg 2 structure is an i5 superstructure of the bcc packing with complete ordering of the erbium, ruthenium, and magnesium atoms. Layers of compressed, ruthenium-centered erbium cubes (290 pm Er-Ru) alternate with layers of edgesharing magnesium tetrahedra (311 and 338 pm Mg--Mg); a new type of magnesium substructure. Temperature dependent magnetic susceptibility studies confirm the stable trivalent ground states of the rare earth elements. Lu 2 RuMg 2 is a Pauli paramagnet and the remaining four compounds show Curie paramagnetism. Dy 2 RuMg 2 and Ho 2 RuMg 2 are accompanied by antiferromagnetic ordering at 8.9(1) and 3.6(1) K, respectively.

by Oldenbourg Wissenschaftsverlag, Mu ¨nchen