[Zurück]

U. Killer, E. Scheidt, H. Michor, J. Hemberger, H.A. Krug von Nidda, W. Scherer:
"Possible canted antiferromagnetism in UCu₉Sn₄*";
Physica B: Condensed Matter, 359-361 (2005), S. 1036 - 1038.

Possible canted antiferromagnetism in UCu₉Sn₄*

U. Killer a, E.-W. Scheidt a, H. Michor b, J. Hemberger c, H.A. Krug von Nidda c and W. Scherer a

a Chemische Physik und Materialwissenschaften, Institut fur Physik, Universität Augsburg, D-86159 Augsburg, Germany
b Institut für Festkörperphysik, TU Wien, 1040 Wien, Austria
c EP V, Elektronische Korrelationen und Magnetismus, Institut für Physik, Universität Augsburg, D-86159 Augsburg, Germany

Available online 19 February 2005.

Abstract

We report on the new compound UCu₉Sn₄ which crystallizes in the tetragonal structure I4/mcm with lattice parameters a = 8.6000 A° and c = 12.359 A°. This compound is isotyp to the ferromagnetic systems RECu₉Sn₄ (RE=Ce, Pr, Nd) with Curie temperatures T_C=5.5, 10.5 and 15 K, respectively. UCu₉Sn₄ exhibits an uncommon magnetic behavior resulting in three different electronic phase transitions. Below 105 K the sample undergoes a valence transition accompanied by an entropy change of 0.5 R ln 2. At 32 K a small hump in the specific heat and a flattening out in the susceptibility curve probably indicate the onset of helical spin-order. To lower temperatures a second transition to antiferromagnetic ordering occurs which develops a small ferromagnetic contribution on lowering the temperature further. These results strongly hinting for canted antiferromagnetism in UCu₉Sn₄.

Keywords: Valence transition; Canted antiferromagnetism

PACS: 75.20.En; 75.30.Kz; 75.50.Ee

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC05937919

http://dx.doi.org/10.1016/j.physb.2005.01.416