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Publications in Scientific Journals:

N. Melnychenkc-Koblyuk, A. Grytsiv, P. Rogl, S. Rotter, E. Bauer, G. Durand, H. Kaldarar, R. Lackner, H. Michor, E. Royanian, M. Koza, G. Giester:
"Clathrate formation in the Ba-Pd-Ge system: Phase equilibria, crystal structure, and physical properties";
Physical Review B, 76 (2007), 144118-1 - 144118-11.



English abstract:
Clathrate formation in the Ba-Pd-Ge system: Phase equilibria, crystal structure, and physical properties
N. Melnychenko-Koblyuk, A. Grytsiv, P. Rogl, and M. Rotter

Institute of Physical Chemistry, University of Vienna, A-1090 Wien, Austria
E. Bauer, G. Durand, H. Kaldarar, R. Lackner, H. Michor, and E. Royanian

Institute of Solid State Physics, Vienna University of Technology, A-1040 Wien, Austria
M. Koza

Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble, France
G. Giester

Institute of Mineralogy and Crystallography, University of Vienna, Althanstrasse 14, A-1090 Wien, Austria
(Received 6 May 2007; published 31 October 2007)

Phase relations at subsolidus temperatures as well as at T=800 C, crystallographic data, electrical and thermal transport measurements, and heat capacity data are reported for several compositions within the clathrate type-I solid solution: Ba8PdxGe46−x−y y ( is a vacancy). The solid solution derives from binary clathrate Ba8Ge43 3 with a solubility limit of 3.8 Pd atoms per formula unit at T=800 C. Structural investigations throughout the homogeneity region confirm cubic primitive symmetry consistent with the space group type Pmn and lattice parameters ranging from a=1.0657(2) nm for Ba8Ge433 to a=1.077 41(2) nm for Ba8Pd3.8Ge42.2 0.0. The primary field of clathrate crystallization has been elucidated from micrography and differential thermal analyses. Both heat capacity and inelastic neutron diffraction define a low-lying, almost localized, phonon branch. Studies of transport properties evidence electrons as the majority charge carriers for most of the homogeneity region; however, at the Pd-rich limit, holes dominate the electronic transport. The crossover between both regimes provides appropriate conditions for attractively high Seebeck values. The lattice contribution dominates the overall thermal conductivity.


"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1103/PhysRevB.76.144118

Electronic version of the publication:
http://link.aps.org/abstract/PRB/v76/e144118


Created from the Publication Database of the Vienna University of Technology.