J. Phys. IV France
Volume 118, November 2004
Page(s) 333 - 341

J. Phys. IV France 118 (2004) 333-341

DOI: 10.1051/jp4:2004118039

X-ray scattering evidence of a new short range order or correlation in the high Tc superconductor Bi2Sr2CaCu2O $_{8+\delta}$

S. Megtert1, J. Avila2, M. Izquierdo2, P.A. Albouy3, G. Gu4, M.C. Asensio2 and R. Comes1

1  Laboratoire pour l'Utilisation du Rayonnement Électromagnétique (LURE), Bât. 209D, U.P.S. 91898 Orsay, France
2  Instituto de Ciencia de Materiales de Madrid, CsiC, Cantoblanco, 28049 Madrid, Spain
3  Laboratoire de Physique des Solides, Bât. 510, U.P.S. 91898 Orsay, France
4  Physics Department, Brookhaven National Geographic, USA

Synchrotron X-ray diffuse scattering experiments performed on a single domain optimally doped crystal of Bi2Sr2CaCu2O $_{8+\delta}$ ( ${\rm Tc} \,\char93 \, 91 ^{\circ}$K) have revealed a new displacive short range order corresponding to a local doubling of the unit cell along the orthorhombic a$_{\rm o}$ direction, thus perpendicular to the commonly reported q$_{\rm b}$ = 0.21 super-structure modulation. The analysis of the X-Ray diffuse structure shows that it has 2D (Dimensional) character, the planar domains being parallel to the a-b conduction plane with an in plane size of about 60 Å at room temperature. Experiments as a function of the temperature (down to 37 K) show that this local order is still present in the superconducting state with no significant change in domain size.

© EDP Sciences 2004