[Zurück]

T. Le Bihan, S. Heathman, M. Idiri, G.H. Lander, J.M. Wills, A.C. Lawson, A. Lindbaum:
"Structural behavior of [alpha] -uranium with pressures to 100 GPa";
Physical Review B, 67 (2003), S. 134102-1 - 134102-6.

Structural behavior of [alpha] -uranium with pressures to 100 GPa

T. Le Bihan,1 S. Heathman,2 M. Idiri,2 G. H. Lander,2,3 J. M. Wills,3 A. C. Lawson,3 and A. Lindbaum4 1European Synchrotron Radiation Facility, Boite Postale 220, F-38043 Grenoble Cedex, France
2European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, D-76125 Karlsruhe, Germany
3Los Alamos National Laboratory, Los Alamos, New Mexico 87545
4Institute for Solid State Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10/138, A-1040 Wien, Austria

(Received 2 December 2002; published 3 April 2003)

The structural behavior of [alpha] -uranium at room temperature has been studied up to 100 GPa in diamond anvil cells using angle-dispersive x-ray diffraction at a synchrotron source. The orthorhombic Cmcm structure is stable to at least 100 GPa. We present details of the variation of all structural parameters, derived from Rietveld analysis of the diffraction patterns: the lattice parameters a, b, and c, and the positional parameter y, as a function of pressure. Precise data, as well as the use of different media for the pressure transmission, allow us to question previous values of several parameters deduced by x-ray diffraction, especially the bulk modulus, and we obtain a revised bulk modulus of B0 = 104(2) GPa with B [₀^[prime]] = 6.2(2). We have also performed accurate (zero-temperature) electronic structure calculations with full structural relaxation up to 100 GPa to test theory against our experimental results. The magnitude and trends of the calculated structural parameters are in reasonable agreement with experiment. In contrast, our bulk modulus calculated at our zero-pressure volume is B0 = 136 GPa and B [₀^[prime]] = 5.07, in agreement with previous calculations, differing markedly from experimental values. ©2003 The American Physical Society

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04405761

http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRBMDO000067000013134102000001&idtype=cvips&gifs=yes