Preparation and characterization of alkaline-earth substituted superconducting La/sub 2/CuO/sub 4/

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · Mater. Res. Bull.; (United States)

DOI:https://doi.org/10.1016/0025-5408(87)90037-7· OSTI ID:6294382

Bednorz, J G; Takashige, M; Muller, K A

Metallic-oxygen deficient compounds in ternary systems MO-La/sub 2/O/sub 3/-CuO with M = Ca, Sr, Ba have been prepared by coprecipitation and subsequent low-temperature solid-state reaction, as well as by high-temperature reaction from the corresponding oxides and carbonates. Substitution of trivalent La by divalent alkaline-earth ions results in sharp drops in resistivity in the 30-40K range, first discovered for the Ba-La-Cu-O system. Room-temperature X-ray powder diffraction shows the presence of a perovskite-like layer-type phase of K/sub 2/NiF/sub 4/-type to be responsible for the high T/sub c/ superconductivity. For single-phase samples of La/sub 2/CuO/sub 4/:M composition, the resistivity drop and especially the onset of the diamagnetic susceptibility are enhanced, and occur near the composition where an orthorhombic-to-tetragonal structural phase transition is detected by X-ray diffraction.

• Research Organization: IBM Research Div., Zurich Research Lab., 8803 Ruschlikon
• OSTI ID: 6294382
• Journal Information: Mater. Res. Bull.; (United States), Journal Name: Mater. Res. Bull.; (United States) Vol. 22:6; ISSN MRBUA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360602 -- Other Materials-- Structure & Phase Studies
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION YIELD
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
COPRECIPITATION
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
NICKEL COMPOUNDS
NICKEL FLUORIDES
ORTHORHOMBIC LATTICES
OXIDES
OXYGEN COMPOUNDS
PEROVSKITES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
POTASSIUM COMPOUNDS
POTASSIUM FLUORIDES
PRECIPITATION
RARE EARTH COMPOUNDS
SCATTERING
SEPARATION PROCESSES
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
STRUCTURAL CHEMICAL ANALYSIS
SUPERCONDUCTIVITY
SYNTHESIS
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS
VALENCE
VERY LOW TEMPERATURE
X-RAY DIFFRACTION
YIELDS