US EPA

1442387 

Journal Article 

High pressure studies on uranium and thorium silicide compounds: Experiment and theory 

Yagoubi, S; Heathman, S; Svane, A; Vaitheeswaran, G; Heines, P; Griveau, JC; Le Bihan, T; Idiri, M; Wastin, F; Caciuffo, R 

2013 

Yes 

Journal of Alloys and Compounds
ISSN: 0925-8388 

546 

63-71 

10.1016/j.jallcom.2012.07.094 

WOS:000311503000009 

The actinide silicides ThSi, USi and USi2 have been studied
under high pressure using both theory and experiment. High pressure synchrotron X-ray diffraction
experiments were performed on polycrystalline samples in diamond anvil cells at room temperature
and for pressures up to 54, 52 and 26 GPa, for ThSi, USi and USi2, respectively. At ambient
conditions, the uranium silicides crystallize in tetragonal structures (space groups: I4/mmm for
USi and I4(1)/amd for USi2), while ThSi adopts an orthorhombic structure (space group: Pbnm)
(including an anharmonic analysis of the silicon). These structures are found to be stable with
no structural transitions observed up to the highest pressures achieved. The zero-pressure bulk
modulus B-0 and its pressure derivative B'(0) at ambient pressure are obtained from the measured
P-V relations. The experiments are accompanied by first principles calculations using the full-
potential linear muffin-tin orbital method within the generalized gradient approximation for
exchange-correlation effects. Experimental results are well reproduced by the calculated equation
of state and ground state properties. (C) 2012 Elsevier B.V. All rights reserved. 

Actinide intermetallics; 5f Electrons; High pressure; Synchrotron radiation