We employ La139 NMR spectroscopy as a structural probe of metallic La2CuO4+δ. We find a distribution of lateral displacements of the oxygen atoms which form the apices of the oxygen octahedra. We directly observe a wide distribution of structures of the La-O layer; this distribution is strongly temperature dependent. We present copper NQR spectra which reveal a second, unexplained, copper site in the CuO2 planes. We show that these features are not manifestations of disturbances of the lattice by interstitial dopants, but are the intrinsic response of La2CuO4+δ to doped holes.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)