Change of the in-plane Cu–O bond distribution in La2CuO4.1 across TcTc

Cu KK-edge X-ray absorption fine structure (XAFS) on La2CuO4.1 has been used to study the radial Cu–O distribution function across the superconducting transition. Fits to the isolated Cu–O XAFS signal show the presence of a non-Gaussian distribution function for temperatures away from the superconducting transition temperature. However, this distribution becomes more harmonic in the vicinity of the superconducting transition temperature TcTc. The results provide evidence for the coupling between the local atomic dynamics and the particles involved in the superconductivity.