PT Journal AU Frello, T Andersen, NH Madsen, J Abrahamsen, AB Zimmermann, M Niemöller, T Schneider, JR Wolf, T TI Oxygen-ordering superstructures in NbBa₂Cu₃O₆̣₅ single crystals investigated by hard-x-ray diffraction SO Physical Review B PY 2000 BP R9253 VL 61 LA english ER