Evidence for a Local Structural Change in La2CuO4.1 Across the Superconducting Transition

Abstract

Polarized Cu—K edge XAFS (X-ray absorption fine structure) on La2CuO4.1 indicate that the radial distribution function of the copper in plane oxygen pairs is a two-site distribution, in agreement with the results found by Bianconi et al. for temperatures below the appearance of a pseudogap. Additionally we find evidence of a change in this distribution across the superconducting transition, suggesting coupling between the local lattice structure and the charged particles involved in the superconductivity.