[Zurück]

M. Rotter, A. Grytsiv, X. Chen, P. Rogl, R. Podloucky, W. Wolf, V. Witusiewicz, A. Saccone, H. Noel, M. Doerr, A. Lindbaum, H. Michor, E. Bauer, S. Heathman, W. Kockelmann, J. Taylor:
"Structural, thermodynamic, and transport properties of Laves-phase ZrMn₂ from x-ray and neutron diffraction and first principles";
Physical Review B, 74 (2006), S. 224109-1 - 224109-10.

Structural, thermodynamic, and transport properties of Laves-phase ZrMn₂ from x-ray and neutron diffraction and first principles

M. Rotter,1 A. Grytsiv,1 Xing-Qiu Chen,1,2 P. Rogl,1 R. Podloucky,1 W. Wolf,3 V. T. Witusiewicz,4 A. Saccone,5 H. Noel,6 M. Doerr,7 A. Lindbaum,8 H. Michor,8 E. Bauer,8 S. Heathman,9 W. Kockelmann,10 and J. Taylor10

1 Institut für Physikalische Chemie, Universität Wien, Währingerstrasse 42, A-1090 Wien, Austria
2 School of Material and Metallurgy, Northeastern University, Shenyang, People's Republic of China
3 Materials Design, 44, av. F.-A. Bartholdi, 72000 Le Mans, France
4 ACCESS Materials & Processes, Intzestrasse 5, D-52072 Aachen, Germany
5 Dipartimento di Chimica e Chimica Industriale, Universit`a degli Studi di Genova, via Dodecaneso 31, 16146 Genova, Italy
6 Laboratorie de Chimie du Solide et Inorganique Moléculaire, UMR 6511 CNRS Université de Rennes 1, Avenue du Général Leclerc, F-35042 Rennes, France
7 Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden, Germany
8 Institut für Festkörperphysik, Technische Universität Wien, A-1040 Wien, Austria
9 European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, D-76125 Karlsruhe, Germany
10 Rutherford Appleton Laboratory, ISIS Facility, Chilton, OX11 0Qx, United Kingdom

Recently, the prediction of structural degeneracy for the ground state of ZrMn₂ by ab initio methods has stimulated research on this system. We investigated the structural and thermodynamic properties by single crystal and powder x-ray diffraction (at zero and high pressure) as well as by neutron powder diffraction, demonstrating that the C14 Laves phase structure is stable down to a temperature of 4.2 K and up to applied pressure of 56 GPa. The bulk modulus and enthalpy of formation (measured by high-temperature drop calorimetric experiments) of ZrMn₂ are found to be 150 GPa and -66.6 kJ (mol of f.u.)^-1, respectively, in nice agreement with the ab initio calculated results. The experimental bulk thermal-expansion data of ZrMn₂ resembles that of a typical metal. However, the temperature-dependent electrical resisitivity shows that there is a power law with n~1.1 at low temperature quite different from simple metals which originates probably from scattering of the charge carriers on the frustrated Mn moments. The phonons have been investigated in detail by comparing results of ab initio calculations with neutron spectra and experimental specific-heat data.

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC06588224

http://link.aps.org/abstract/PRB/v74/e224109