Comparative study of superconducting LaBa/sub 2/Cu/sub 3/O/sub 7-delta/ and La/sub 3-x/Ba/sub 3+x/Cu/sub 6/O/sup 14+delta/*

Journal Article · Thu Mar 31 23:00:00 EST 1988 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(88)90154-5· OSTI ID:7007100

Ganapathi, L; Ganguli, A K; Mohan Ram, R A; Rao, C N.R.

Based on X-ray diffraction and electron microscopy it is shown that oxides of the general formula LaBa/sub 2/Cu/sub 3/O/sub 7-delta/ become tetragonal when delta deviates slightly from 0. This tetragonal structure is similar to that of La/sub 3-x/Ba/sub 3+x/Cu/sub 6/O/sub 14+delta/, with a cubic perovskite subcell and triple periodicity. Electron micrographs of these tetragonal oxides show 90/sup 0/ microdomains. Orthorhombic LaBa/sub 2/Cu/sub 3/O/sub 7-delta/ with high T/sub c/ (approx. 77 K) is found only when delta approx. = 0; this sample is subject to formation of twins. Fluorine substitution seems to favor superconductivity.

• Research Organization: Indian Institute of Science, Bangalore (India)
• OSTI ID: 7007100
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 73:2; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
DATA
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
INFORMATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MICROSCOPY
NUMERICAL DATA
ORTHORHOMBIC LATTICES
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SCATTERING
SUPERCONDUCTIVITY
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION