Europhys. Lett.
Volume 66, Number 5, June 2004
Page(s) 722 - 728
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 May 2004
Europhys. Lett., 66 (5) , pp. 722-728 (2004)
DOI: 10.1209/epl/i2004-10030-0

Interplay between freezing and superconductivity in the optimally doped $\chem{La_{1.65}Eu_{0.2}Sr_{0.15}CuO_4}$ under hydrostatic pressure

B. Simovic1, M. Nicklas2, P. C. Hammel3, M. Hücker4, B. Büchner5 and J. D. Thompson6

1  Laboratorium für Festkörperphysik HPF - ETH Hönggerberg CH-8093 Zürich, Switzerland
2  Max Planck Institute for Chemical Physics of Solids Noethnitzer Str. 40, D-01187 Dresden, Germany
3  Department of Physics, The Ohio State University - Columbus, OH 43210, USA
4  Physics Department, Brookhaven National Laboratory - Upton, NY 11973, USA
5  RWTH Aachen - D-52056 Aachen, Germany
6  Condensed Matter and Thermal Physics, Los Alamos National Laboratory Los Alamos, NM 8754, USA

(Received 22 January 2004; accepted in final form 6 April 2004)

We study the electronic properties of a $\chem{La_{1.65}Eu_{0.2}Sr_{0.15}CuO_4}$ single crystal under hydrostatic pressure up to 2.9 $\un{GPa}$. Both the freezing of the $\chem{Cu}$ 3d moments and the structural transition from the orthorhombic (LTO) to the tetragonal (LTT) phase are observed via the relaxation of the nuclear magnetization of $\chem{{}^{139}La}$ nuclei. Resistivity and magnetic susceptibility measurements have been carried out under pressure on the same sample. The combination of all data reveals the connection between glassy dynamics, charge localization and the disappearance of superconductivity in the LTT phase.

74.72.Dn - $\chem{La}$-based cuprates.
74.25.Ha - Magnetic properties.
74.62.Fj - Pressure effects.

© EDP Sciences 2004