@article{2977550, title = "Main- and superstructure by X-ray scattering for annealed single crystal of YBa2Cu3O6.5", author = "Grybos, J. and Wabia, M. and Kubanek, F. and Guskos, N.", journal = "Physica C: Superconductivity and its Applications", year = "1999", volume = "320", number = "1", pages = "51-64", publisher = "Elsevier Science Publishers B.V., Amsterdam", issn = "0921-4534", doi = "10.1016/S0921-4534(99)00278-6", keywords = "Annealing; Atoms; Copper; Crystal atomic structure; Mathematical models; Oxygen; Phase separation; Reflection; Single crystals; Superconducting transition temperature; X ray diffraction analysis; X ray scattering, Apex oxygen; Copper superconducting plane; Diffuse scattering; Superstructure reflections, Yttrium barium copper oxides", abstract = "A single crystal of YBa2Cu3O6.5 was annealed at 430, 510, 570 and 590 K in the furnace of a four-circle X-ray diffractometer, cooled down slowly to room temperature and investigated structurally. From the dataset of about 200 reflections with 40 superstructure reflections, the main- and superstructure models have been derived. Displacements of Cu atoms, changes of oxygen populations in the basal plane and the small displacements of Y, Ba and apex-oxygens were observed. The changes of atom positions have been correlated with the superconducting transition temperature Tc. With increasing annealing temperature, the phase separation, a characteristic diffuse scattering in the 00l-direction, changes of oxygen population in the basal plane and after annealing at 430 K, the disappearance of twinned reflections in the a*-b* plane have been seen." }