Structural chemistry and magnetic behavior of binary uranium silicides

Journal Article · Wed Apr 01 04:00:00 EST 1992 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1016/0022-4596(92)90048-Z· OSTI ID:7229034

Remschnig, K; Rogl, P ^[1]; Bihan, T le; Noel, H ^[2]

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1. Univ. Wien, Waehringerstrasse (Austria)
2. Univ. de Rennes I (France)

Binary uranium silicides have been thoroughly reinvestigated with respect to crystal chemistry and magnetic properties; for most compounds, magnetic studies have been carried out at low temperatures for the first time (2 to 300 K, 0 to 5 T). Formation of all known binary silicides has been confirmed: U{sub 3}Si, U{sub 3}Si{sub 2} (U{sub 3}Si{sub 2}-type), USi (USi-type), U{sub 3}Si{sub 5} (defect AlB{sub 2}-type), USi{sub 1.88} (defect ThSi{sub 2}-type) and USi{sub 3} (Cu{sub 3}Au-type). At the composition U{sub 3}Si{sub {approximately}5} three different phases have been observed: the defect AlB{sub 2}-type as well as a phase separation into two orthorhombically distorted AlB{sub 2}-type related phases. USi{sub 2{minus}x} with the tetragonal defect ThSi{sub 2}-type structure at its silicon poor phase boundary was found to be in equilibrium with USi{sub 2{minus}x} of the orthorhombic defect GdSi{sub 2} type. Precise U-U distances have been derived from X-ray single crystal counter data for U{sub 3}Si{sub 2}, USi, for the AlB{sub 2}-type subcell of U{sub 3}Si{sub 5}, and for USi{sub 1.84} (defect ThSi{sub 2}-type). From susceptibility measurements, a band type paramagnetism was observed for U{sub 3}Si{sub 2}, whereas a temperature independent paramagnetism was confirmed for USi{sub 3}. Curie-Weiss paramagnetism was encountered within the investigated temperature range for U{sub 3}Si{sub 5} and USi{sub 1.88}. A modified Curie-Weiss law was revealed for USi with the USi-type, whereas ferromagnetic ordering at T{sub c} = 125 K was observed for the oxygen stabilized 'USi' with the FeB-type. Magnetism of the uranium silicides is discussed as a function of the distant dependent 5f-5f electron overlap and d-f electron hybridization. No superconductivity was observed above 2 K.

• OSTI ID: 7229034
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 97:2; ISSN 0022-4596; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
ACTINIDE COMPOUNDS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EXPERIMENTAL DATA
INFORMATION
MAGNETIC PROPERTIES
MAGNETISM
NUMERICAL DATA
PARAMAGNETISM
PHASE STUDIES
PHYSICAL PROPERTIES
SCATTERING
SILICIDES
SILICON COMPOUNDS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
URANIUM COMPOUNDS
URANIUM SILICIDES
X-RAY DIFFRACTION