Superconductivity and Cu valence of Bi-Sr-Ca-Cu-O thin films

Journal Article · Tue Nov 01 04:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.9201· OSTI ID:6725965

Kohiki, S; Hirochi, K; Adachi, H; Setsune, K; Wasa, K

Bi-Sr-Ca-Cu-O superconducting films were prepared by rf magnetron sputtering using a target with modulated composition and successive annealing in oxygen. The resistivity and Cu valence of the films varied before and after annealing. The zero-resistance temperature of the films was 10 K before the annealing, and rose up to 96 K (midpoint 105 K) after annealing. Essentially no change in the characteristic layer spacing (d value) of approx. =18A, corresponding to c/2, was observed before and after the annealing as seen by x-ray diffraction. The Cu valence of the films was investigated by x-ray photoemission before and after annealing. The photoemission core-level spectra and LMM Auger emission spectra revealed that the Cu valence after annealing became larger than that obtained before annealing. The superconductivity obviously is correlated with the Cu valence of the films.

• Research Organization: Central Research Laboratory, Matsushita Electric Industries, Moriguchi, Osaka 570, Japan
• OSTI ID: 6725965
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:13; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
ANNEALING
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COPPER
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
EMISSION
FILMS
HEAT TREATMENTS
METALS
OXIDES
OXYGEN COMPOUNDS
PHOTOEMISSION
PHYSICAL PROPERTIES
SECONDARY EMISSION
STRONTIUM COMPOUNDS
SUPERCONDUCTING FILMS
SUPERCONDUCTIVITY
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VALENCE
VARIATIONS