Details

Autor(en) / Beteiligte

• Fiká ek, J
• Prokleška, J
• Prchal, J
• Custers, J
• Sechovský, V

Titel

Nature of the magnetic ground state in the mixed valence compound CeRuSn: a single-crystal study

Ist Teil von

• Journal of physics. Condensed matter, 2013-10, Vol.25 (41), p.416006-416006

Ort / Verlag

Bristol: IOP Publishing

Erscheinungsjahr

2013

Quelle

MEDLINE

Beschreibungen/Notizen

• We report on detailed low-temperature measurements of the magnetization, the specific heat and the electrical resistivity on high-quality CeRuSn single crystals. The compound orders antiferromagnetically at TN = 2.8 K with the Ce3+ ions locked within the a-c plane of the monoclinic structure. Magnetization shows that below TN CeRuSn undergoes a metamagnetic transition when applying a magnetic field of 1.5 and 0.8 T along the a- and c-axis, respectively. This transition manifests in a tremendous negative jump of ∼25% in the magnetoresistance. The value of the saturated magnetization along the easy magnetization direction (c-axis) and the magnetic entropy above TN derived from specific heat data correspond to the scenario of only one third of the Ce ions in the compound being trivalent and carrying a stable Ce3+ magnetic moment, whereas the other two thirds of the Ce ions are in a nonmagnetic tetravalent and/or mixed valence state. This is consistent with the low-temperature CeRuSn crystal structure i.e., a superstructure consisting of three unit cells of the CeCoAl type piled up along the c-axis, and in which the Ce3+ ions are characterized by large distances from the Ru ligands while the Ce-Ru distances of the other Ce ions are much shorter causing a strong 4f-ligand hybridization and hence leading to tetravalent and/or mixed valence Ce ions.