caa a22 4500 445380306 CHVBK 20180317143015.0 cr unu---uuuuu 170323e20110401xx s 000 0 eng 10.1007/s10948-010-1105-1 doi (NATIONALLICENCE)springer-10.1007/s10948-010-1105-1 Lattice Anomalies in the Oxygen Deficient NdFeAsO Superconductor [Elektronische Daten] [M. Calamiotou, I. Margiolaki, Z. Ren, Z. Zhao, E. Siranidi, E. Liarokapis] We compare the results of high-resolution synchrotron X-ray powder diffraction with low-temperature spectroscopic studies on the oxygen deficient NdFeAsO0.85 superconductor. IR results indicate that a certain mode related to vibrations of the As ions softens at low temperatures. By employing a dense temperature sampling we have managed to reveal unnoticed structural modifications that start around ∼180K, as the anomaly of the IR mode, and disappear at the transition temperature. The data show smaller structural changes in the Nd-O charge reservoir layer, while in the superconducting layer the FeAs4 tetrahedron shows gradual modifications below ∼180K, which peak around 140K and then suddenly disappear atT c. The observed lattice anomalies are not connected with a structural phase transition or an AF ordering; they are more evident in the superconducting Fe-As planes, and disappear across T c, pointing to a connection to superconductivity. Springer Science+Business Media, LLC, 2010 Oxypnictides nationallicence Superconductivity nationallicence Lattice effects nationallicence Structural anomalies nationallicence Calamiotou M. Solid State Physics Department, University of Athens, 15784, Athens, Greece aut Margiolaki I. ESRF, BP 220, 38043, Grenoble Cedex 9, France aut Ren Z. National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing, China aut Zhao Z. National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing, China aut Siranidi E. Department of Physics, National Technical University of Athens, 157 80, Athens, Greece aut Liarokapis E. Department of Physics, National Technical University of Athens, 157 80, Athens, Greece aut Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/3(2011-04-01), 1181-1184 1557-1939 24:3<1181 2011 24 10948 https://doi.org/10.1007/s10948-010-1105-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10948-010-1105-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Calamiotou M. Solid State Physics Department, University of Athens, 15784, Athens, Greece aut NATIONALLICENCE 700 1- Margiolaki I. ESRF, BP 220, 38043, Grenoble Cedex 9, France aut NATIONALLICENCE 700 1- Ren Z. National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing, China aut NATIONALLICENCE 700 1- Zhao Z. National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing, China aut NATIONALLICENCE 700 1- Siranidi E. Department of Physics, National Technical University of Athens, 157 80, Athens, Greece aut NATIONALLICENCE 700 1- Liarokapis E. Department of Physics, National Technical University of Athens, 157 80, Athens, Greece aut NATIONALLICENCE 773 0- Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/3(2011-04-01), 1181-1184 1557-1939 24:3<1181 2011 24 10948 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer