The ternary system cerium-palladium-silicon

Journal Article · Tue Sep 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.06.022· OSTI ID:21370583

Lipatov, Alexey ^[1]; Gribanov, Alexander ^[1]; Grytsiv, Andriy ^[1]; Rogl, Peter ^[1]; Murashova, Elena; Seropegin, Yurii ^[2]; Giester, Gerald ^[3]; Kalmykov, Konstantin ^[2]

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1. Institute of Physical Chemistry, University of Vienna, Waehringerstrasse 42, A-1090 Wien (Austria)
2. Chemistry Department of the Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow (Russian Federation)
3. Institute of Mineralogy and Crystallography, University of Vienna, Althanstrasse 14, A-1090 Wien (Austria)

Phase relations in the ternary system Ce-Pd-Si have been established for the isothermal section at 800 deg. C based on X-ray powder diffraction and EMPA techniques on about 130 alloys, which were prepared by arc-melting under argon or powder reaction sintering. Eighteen ternary compounds have been observed to participate in the phase equilibria at 800 deg. C. Atom order was determined by direct methods from X-ray single-crystal counter data for the crystal structures of tau{sub 8}-Ce{sub 3}Pd{sub 4}Si{sub 4} (U{sub 3}Ni{sub 4}Si{sub 4}-type, Immm; a=0.41618(1), b=0.42640(1), c=2.45744(7) nm), tau{sub 16}-Ce{sub 2}Pd{sub 14}Si (own structure type, P4/nmm; a=0.88832(2), c=0.69600(2) nm) and also for tau{sub 18}-CePd{sub 1-x}Si{sub x} (x=0.07; FeB-type, Pnma; a=0.74422(5), b=0.45548(3), c=0.58569(4) nm). Rietveld refinements established the atom arrangement in the structures of tau{sub 5}-Ce{sub 3}PdSi{sub 3} (Ba{sub 3}Al{sub 2}Ge{sub 2}-type, Immm; a=0.41207(1), b=0.43026(1), c=1.84069(4) nm) and tau{sub 13}-Ce{sub 3-x}Pd{sub 20+x}Si{sub 6} (0<=x<=1, Co{sub 20}Al{sub 3}B{sub 6}-type, Fm3-barm; a=1.21527(2) nm). The ternary compound Ce{sub 2}Pd{sub 3}Si{sub 3} (structure-type Ce{sub 2}Rh{sub 1.35}Ge{sub 4.65}, Pmmn; a=0.42040(1), b=0.42247(1), c=1.72444(3) nm) was detected as a high-temperature compound, however, does not participate in the equilibria at 800 deg. C. Phase equilibria in Ce-Pd-Si are characterized by the absence of cerium solubility in palladium silicides. Mutual solubility among cerium silicides and cerium-palladium compounds are significant whereby random substitution of the almost equally sized atom species palladium and silicon is reflected in extended homogeneous regions at constant Ce-content such as for tau{sub 2}-Ce(Pd{sub x}Si{sub 1-x}){sub 2} (AlB{sub 2}-derivative type), tau{sub 6}-Ce(Pd{sub x}Si{sub 1-x}){sub 2} (ThSi{sub 2}-type) and tau{sub 7}-CePd{sub 2-x}Si{sub 2+x}. The crystal structures of compounds tau{sub 4}-Ce{sub a}pprox{sub 8}Pd{sub a}pprox{sub 46}Si{sub a}pprox{sub 46}, tau{sub 12}-Ce{sub a}pprox{sub 29}Pd{sub a}pprox{sub 49}Si{sub a}pprox{sub 22}, tau{sub 15}-Ce{sub a}pprox{sub 22}Pd{sub a}pprox{sub 67}Si{sub a}pprox{sub 11}, tau{sub 17}-Ce{sub a}pprox{sub 5}Pd{sub a}pprox{sub 77}Si{sub a}pprox{sub 18} and tau{sub 18}-CePd{sub 1-x}Si{sub x} (xapprox0.1) are still unknown. - Abstract: Phase relations in the ternary system Ce-Pd-Si have been established for the isothermal section at 800 deg. C based on X-ray powder diffraction, metallography, SEM and EMPA techniques on about 130 alloys. 18 ternary compounds were observed. Display Omitted

• OSTI ID: 21370583
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 9; Other Information: DOI: 10.1016/j.jssc.2009.06.022; PII: S0022-4596(09)00281-3; Copyright (c) 2009 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
ARGON
CERIUM ALLOYS
CERIUM SILICIDES
CUBIC LATTICES
MELTING
MONOCRYSTALS
ORTHORHOMBIC LATTICES
PALLADIUM ALLOYS
PALLADIUM SILICIDES
PHASE DIAGRAMS
SCANNING ELECTRON MICROSCOPY
SILICON ALLOYS
SINTERING
SOLUBILITY
TEMPERATURE RANGE 1000-4000 K
TETRAGONAL LATTICES
X-RAY DIFFRACTION
ALLOYS
CERIUM COMPOUNDS
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DIAGRAMS
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
FABRICATION
FLUIDS
GASES
INFORMATION
MICROSCOPY
NONMETALS
PALLADIUM COMPOUNDS
PHASE TRANSFORMATIONS
PLATINUM METAL ALLOYS
RARE EARTH ALLOYS
RARE EARTH COMPOUNDS
RARE GASES
SCATTERING
SILICIDES
SILICON COMPOUNDS
TEMPERATURE RANGE
TRANSITION ELEMENT ALLOYS
TRANSITION ELEMENT COMPOUNDS