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Z. Naturforsch. 2013,
68b, 960 – 970
doi:10.5560/ZNB.2013-3176
Cerium Valence Change in the Solid Solutions Ce(Rh1−xRux)Sn
1 Institut für Anorganische und Analytische Chemie and NRW Graduate School of Chemistry, Universit?t Münster, Corrensstra?e 30, D-48149 Münster, Germany
2 SNBL at ESRF, European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220, Grenoble, France
3 CNRS, Universit? de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, 33608 Pessac-Cedex, France
Reprint requests to R. Pöttgen. E-mail:
pottgen@uni-muenster.de
Received July 1, 2013 / published online September 4, 2013
The solid solutions Ce(Rh1−xRux)Sn were investigated by means of susceptibility measurements, specific heat, electrical resistivity, X-ray absorption spectroscopy (XAS), and 119Sn Mössbauer spectroscopy. Magnetic measurements as well as XAS data show a cerium valence change in dependence on the ruthenium content. Higher ruthenium content causes an increase from 3.22 to 3.45 at 300 K. Furthermore χ and χ−1 data indicate valence fluctuation for cerium as a function of temperature. For example, Ce(Rh0.8Ru0.2)Sn exhibits valence fluctuations between 3.42 and 3.32 in the temperature range of 10 to 300 K. This could be proven by using the interconfiguration fluctuation (ICF) model introduced by Sales and Wohlleben.
Cerium valence change does not influence the tin atoms as proven by 119Sn Mössbauer spectroscopy, but it influences the electrical properties. Ce(Rh0.9Ru0.1)Sn behaves like a typical valence fluctuating compound, and higher ruthenium content causes an increase of the metallic behavior.
Key words: Cerium, Intermediate, Valence, Magnetic Properties