Structure and superconductivity in (Bi{sub 0.35}Cu{sub 0.65})Sr{sub 2}YCu{sub 2}O{sub 7} and related materials

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:121644

Jennings, R A; Williams, S P; Greaves, C ^[1]

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1. Univ. of Birmingham (United Kingdom)

The recently reported (Bi/Cu)Sr{sub 2}YCu{sub 2}O{sub 7} phase has been studied by time of flight powder neutron diffraction. The proposed 1212 structure has been confirmed and refinements have shown the oxygen in the (Bi/Cu)O layer is displaced by 0.78{angstrom} from the ideal (1/2,1/2,0) site (P4/mmm space group) along (100). Bond Valence Sum calculations have suggested oxidation states of Bi{sup 5+} and Cu{sup 2+} for the cations in the (Bi/Cu)O layers. The material is non-superconducting and all attempts to induce superconductivity have been unsuccessful. Work on the related material (Ce/Cu)Sr{sub 2}YCu{sub 2}O{sub y} has shown the ideal Ce content to be 0.5 Ce per formula unit. The introduction of Ba (10%) onto the Sr site dramatically increases phase stability and also induces superconductivity (62K).

• Research Organization: National Aeronautics and Space Administration, Washington, DC (United States); National Aeronautics and Space Administration, Houston, TX (United States). Lyndon B. Johnson Space Center
• OSTI ID: 121644
• Report Number(s): CONF-940627--Vol.2; ON: TI95017155
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
HIGH-TC SUPERCONDUCTORS
NEUTRON DIFFRACTION
OXIDATION
STRONTIUM COMPOUNDS
SUPERCONDUCTIVITY
SYNTHESIS
YTTRIUM COMPOUNDS