DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2006 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.82: Poster

Wednesday, March 29, 2006, 14:30–18:30, P1

Possible critical pressure-induced valence fluctuation in EuCu2Ge2 — •Gabriel Alejandro Dionicio1, Heribert Wilhelm1, Zakir Hossain2, and Christoph Geibel11Max-Planck-Institute for Chemical Physics of Solids, 01187 Dresden, Germany — 2Department of Physics, Indian Institute of Technology, Kanpur-208016, India

By means of electrical resistivity measurements under pressure, we investigated the possibility of inducing a valence fluctuating regime in EuCu2Ge2 at low temperatures. The results are discussed in terms of a possible scenario for unconventional superconductivity driven by virtual exchange fluctuation of the charge density [1]. This mechanism was proposed to explain the high pressure superconducting dome in CeCu2(Si0.9Ge0.1)2 [2]. Our porpuse is to look for further candidates where this model might be apply. Some Eu-compounds with the ThCr2Si2 structure have shown a thermal activated continuous crossover from a divalent to a trivalent state, due to the degeneracy of the f7 and f6 configuration. We would like to address the question whether such a degenerated state can be induced by pressure at very low temperatures in EuCu2Ge2, taking into account that this situation seems to be achieved in EuCu2(Si0.7Ge0.3)2. The electrical resistivity measurements were performed up to 10 GPa in the temperature range 100 mK < T < 300 K. A tentative phase diagram is presented and the results are compared with the studies peformed in the alloy CeCu2(SixGe1−x)2.

[1] K. Miyake, H. Maebashi; J. Phys. Soc. Jpn. 71 (2002) 1007

[2] H. Q. Yuan et al; Science 302 (2003) 2104

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2006 > Dresden