The Ce-Ni-Si System Revisited

Autor(en)

Fainan Failamani, Andriy Grytsiv, Jiri Bursik, Gerald Giester, Peter Rogl

Abstrakt

The nickel-rich region of the system Ce-Ni-Si has been reinvestigated utilizing X-ray single-crystal, powder, and electron diffraction as well as electron microprobe and thermal analyses. Two novel hexagonal compounds, τ-Ce_20+xNi_36+ySi_30-z and τ′-Ce_30+xNi_50+ySi_42-z, were identified. The crystal structure of τ-Ce_20+xNi_36+ySi_30-z was derived from single-crystal X-ray diffraction and found to be isotypic with the Sm₁₀Ni_20.8P₁₅-type structure (S.G. P6₃/m, x = 1.8, y = 3.0, z = 1.8, a = 2.07156(2) nm, c = 0.39990(1) nm, R_F = 0.048). Rietveld refinement of τ′-Ce_30+xNi_50+ySi_42-z revealed isotypism with Tb₁₅Ni₂₈P₂₁ (S.G. P6₃/m, a = 2.46926(13) nm, c = 0.40019(3) nm, R_F = 0.058). The compound Ce₃Ni₄Si₂ from X-ray single-crystal analysis was found to crystallize in a novel structure type with monoclinic unit cells (S.G. C2/c, a = 1.54708(3) nm, b = 0.58677(1) nm, c = 0.74331(1) nm, β = 102.985(1)°, R_F = 0.017). This compound belongs to a new homologue series in the RE-Ni-Si system (RE = La and Ce) with general formula of RE_(3×2ⁿ)Ni_{(3×2ⁿ + 1)}Si_(2ⁿ⁺¹); n = 0,1, ..., ∞. The crystal structure of this series is characterized by alternating numbers (2ⁿ) of corner-sharing Si-polyhedral blocks sandwiched between zigzag nickel chains. Higher-order members of this series are produced by the formation of more corner-sharing Si-polyhedral blocks due to removal of nickel chains.

Organisation(en)

Institut für Materialchemie, Institut für Mineralogie und Kristallographie

Externe Organisation(en)

Czech Academy of Sciences, Institut Teknologi Bandung

Journal

Inorganic Chemistry

Band

63

Seiten

8604-8614

Anzahl der Seiten

11

ISSN

0020-1669

DOI

https://doi.org/10.1021/acs.inorgchem.3c04594

Publikationsdatum

05-2024

Peer-reviewed

Ja

ÖFOS 2012

105116 Mineralogie, 105113 Kristallographie

ASJC Scopus Sachgebiete

Physical and Theoretical Chemistry, Inorganic Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/5020a066-14c2-4d1c-a26f-f5be263ab669