TY - JOUR
TI - Main- and superstructure by X-ray scattering for annealed single crystal of YBa2Cu3O6.5
AU - Grybos, J.
AU - Wabia, M.
AU - Kubanek, F.
AU - Guskos, N.
JO - Physica C: Superconductivity and its Applications
PY - 1999
VL - 320
TODO - 1
SP - 51-64
PB - Elsevier Science Publishers B.V., Amsterdam
SN - 0921-4534
TODO - 10.1016/S0921-4534(99)00278-6
TODO - 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
TODO - 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.
ER -