Oxygen ordering and superconductivity in GdBaSrCu3O7-x

Autor(en)

X.Z. Wang, B. Hellebrand, D. Bauerle, M. Strecker, G. Wortmann, W. Lang

Abstrakt

A special preparation process has been developed to stabilise GdBaSrCu3O(7-x) compounds in both tetragonal and orthorhombic structures with oxygen deficiency x close to zero. Powder X-ray diffraction analysis (XRD) gives lattice parameters of a=3.839 Angstrom and c=11.572 Angstrom for a tetragonal structure, and a=3.804 Angstrom, b= 3.863 Angstrom and c=11.588 Angstrom for a typical orthorhombic structure. Gd-155-Mossbauer spectroscopy reveals via the electric quadrupole interaction an asymmetry parameter eta=0.14(6) for the tetragonal phase (T-phase) and eta=0.31(5) for the orthorhombic phase (O-phase). The small asymmetry parameter for the T-phase indicates an oxygen disordering in the basal plane. Superconducting transition temperatures T-c above 80 K were verified for both tetragonal and orthorhombic phases by resistivity and susceptibility measurements. Despite of a similar T-c-value the normal-state transport properties studied by resistivity and Hall effect measurements revealed higher resistivity in the tetragonal phase, which may be caused by both the destruction of the CuO chains and an enhanced scattering introduced by disorder of oxygen atoms in the basal plane.

Organisation(en)

Elektronische Materialeigenschaften

Journal

Physica C: Superconductivity and its Applications

Band

242

Seiten

55-62

Anzahl der Seiten

8

ISSN

0921-4534

DOI

https://doi.org/10.1016/0921-4534(94)02370-0

Publikationsdatum

1995

Peer-reviewed

Ja

ÖFOS 2012

103018 Materialphysik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/58451a69-5a71-4da5-9af9-6ca408a78061