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S. Paschen, S. Budnyk, U. Köhler, Y. Prots, K. Hiebl, F. Steglich, YU. Grin:
"New type-I clathrates with ordered Eu distribution";
Physica B: Condensed Matter, 383 (2006), S. 89 - 92.

New type-I clathrates with ordered Eu distribution

S. Paschen a, S. Budnyk b, U. Köhler b, Yu. Prots b, K. Hiebl c, F. Steglich b and Yu. Grin b

a Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, 1040 Vienna, Austria
b Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
c Department of Physical Chemistry, University of Vienna, Währinger Str. 42, 1090 Vienna, Austria

Available online 11 May 2006.

Abstract

In our search for clathrates containing rare-earth elements we have discovered the three new clathrate-I phases K₆Eu₂Ga₁₀Ge₃₆, K₆Eu₂Zn₅Ge₄₁, and K₆Eu₂Cd₅Ge₄₁. The Eu atoms occupy only the smaller cages (pentagondodecahedra) leading to a fully ordered arrangement of the guest atoms. X-ray absorption spectroscopy and magnetic susceptibility measurements reveal that at room temperature and above Eu is close to divalent in all compounds. Magnetization measurements at low temperatures, however, may indicate slightly reduced magnetic moments for K₆Eu₂Ga₁₀Ge₃₆and K₆Eu₂Zn₅Ge₄₁. The ferromagnetic ordering temperatures of 3.8, 4.0, and 9.3 K for K₆Eu₂Ga₁₀Ge₃₆, K₆Eu₂Zn₅Ge₄₁, and K₆Eu₂Cd₅Ge<sub>41, respectively, are considerably reduced with respect to the 36 K observed for the type-I clathrate β-Eu8Ga16Ge30 where all cages are occupied by Eu.

Keywords: Clathrates; Eu</sub>

Clathrates; Eu

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC06588171

http://dx.doi.org/10.1016/j.physb.2006.03.066