Quaternary germanides formed in molten aluminum: Tb2NiAl4Ge2 and Ce2NiAl6-xGe4-y (x ∼ 0.24, y ∼ 1.34)

Brad Sieve, Pantelis N. Trikalitis, Mercouri G. Kanatzidis

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The intermetallic phases Tb2NiAl4Ge2 and Ce2NiAl6-xGe4-y (x ∼ 0.24, y ∼ 1.34) were synthesized in molten Al at temperatures below 1000°C. Both compounds adopt the tetragonal space group I4/mmm with cell parameters of a = 4.1346(2) Å c = 19.3437(7) Å for Tb2NiAl4Ge2 and a = 4.1951(9) Å and c = 26.524(7) Å for Ce2NiAl6-xGe4-y. The Tb2NiAl4Ge2 structure features NiAl4Ge2 layers separated by a double layer of rare earth ions. The Ce2NiAl6-xGe4-y (x ∼ 0.24, y ∼ 1.34) structure also contains the NiAl4Ge2 layers along with a vacancy defect PbO-type Al2-xGe2-y layer, and is related to the Ce2NiGa10 structure type. Ordering of vacancies cause the formation of a 3ax3b superstructure in the crystal as seen by electron diffraction experiments. Tb2NiAl4Ge2 exhibits Curie-Weiss paramagnetic behavior with an antiferromagnetic transition observed at ∼20 K. Ce2NiAl6-xGe4-y shows a much more complex magnetic behavior possibly due to temperature induced variation in the valency of the Ce atoms.

Original languageEnglish
Pages (from-to)1568-1574
Number of pages7
JournalZeitschrift fur Anorganische und Allgemeine Chemie
Volume628
Issue number7
DOIs
Publication statusPublished - Aug 17 2002

Keywords

  • Aluminium
  • Crystal structure
  • Germanides (quaternary)
  • Magnetic properties
  • Nickel
  • Rare earth elements

ASJC Scopus subject areas

  • Inorganic Chemistry

Fingerprint Dive into the research topics of 'Quaternary germanides formed in molten aluminum: Tb<sub>2</sub>NiAl<sub>4</sub>Ge<sub>2</sub> and Ce<sub>2</sub>NiAl<sub>6-x</sub>Ge<sub>4-y</sub> (x ∼ 0.24, y ∼ 1.34)'. Together they form a unique fingerprint.

  • Cite this