Ternary rare-earth bismuthides RE{sub 5}SiBi{sub 2} and RE{sub 5}GeBi{sub 2} (RE=La-Nd, Gd-Er): Stabilization of the {beta}-Yb{sub 5}Sb{sub 3}-type structure through tetrel substitution

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.10.007· OSTI ID:21494169

Barry, Stephen D; Tkachuk, Andriy V; Bie, Haiying; Blanchard, Peter E.R. ^[1]; Mar, Arthur ^[1]

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1. Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 (Canada)

Ternary bismuthides RE{sub 5}TtBi{sub 2} containing rare-earth (RE=La-Nd, Gd-Er) and tetrel (Tt=Si, Ge) atoms have been prepared by arc-melting of the elements followed by annealing at 800 {sup o}C. They adopt the {beta}-Yb{sub 5}Sb{sub 3}-type structure (Pearson symbol oP32, space group Pnma, Z=4), as revealed through analysis by single-crystal X-ray diffraction on Ce{sub 5}Si{sub 0.869(4)}Bi{sub 2.131(4)} and powder X-ray diffraction on Ce{sub 5}GeBi{sub 2}. Cell parameters for the entire series lie in the ranges of a=12.8-11.8 A, b=9.6-9.0 A, and c=8.4-7.9 A. Solid solubility in Ce{sub 5}Si{sub x}Bi{sub 3-x} and Pr{sub 5}Si{sub x}Bi{sub 3-x} (approximately 0.9{<=}x{<=}1.2, depending on the RE member) is much more limited compared to the antimonides, consistent with a highly ordered structure in which the two possible anion sites are essentially segregated into a smaller one occupied by Tt atoms (CN7) and a larger one occupied by Bi atoms (CN9). Band structure calculations on La{sub 5}SiBi{sub 2} confirm the importance of La-La bonding interactions near the Fermi level. X-ray photoelectron spectra support the presence of partially anionic Bi atoms, as indicated by a small negative binding energy shift relative to elemental Bi. The Ce and Pr members undergo magnetic transitions at low temperatures, possibly involving ferromagnetic interactions, that are strongly influenced by the nature of the Tt atom. -- Graphical Abstract: Tetrel (Si or Ge) and Bi atoms are arranged in an ordered manner in the {beta}-Yb{sub 5}Sb{sub 3}-type structure adopted by RE{sub 5}TtBi{sub 2}. Display Omitted

• OSTI ID: 21494169
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 1; Other Information: DOI: 10.1016/j.jssc.2010.10.007; PII: S0022-4596(10)00461-5; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANIONS
ANNEALING
ANTIMONIDES
BINDING ENERGY
BISMUTH COMPOUNDS
FERMI LEVEL
MAGNETIC PROPERTIES
MELTING
MONOCRYSTALS
ORTHORHOMBIC LATTICES
RARE EARTH COMPOUNDS
SOLUBILITY
SPACE GROUPS
TEMPERATURE RANGE 1000-4000 K
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
ANTIMONY COMPOUNDS
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
ELECTRON SPECTROSCOPY
ENERGY
ENERGY LEVELS
HEAT TREATMENTS
IONS
PHASE TRANSFORMATIONS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
PNICTIDES
SCATTERING
SPECTROSCOPY
SYMMETRY GROUPS
TEMPERATURE RANGE