Formation of the 110-K superconducting phase in Pb-doped Bi-Sr-Ca-Cu-O thin films

Journal Article · Sun Sep 15 04:00:00 EDT 1991 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.349299· OSTI ID:5277976

Kula, W; Sobolewski, R; Gorecka, J; Lewandowski, S J ^[1]

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1. Instytut Fizyki, Polska Akademia Nauk, Al. Lotnikow 32/46, PL-02668 Warszawa (Poland)

Investigation of the 110-K Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub {ital x}} phase formation in superconducting thin films of Bi-based cuprates is reported. The films were dc magnetron sputtered from single Bi(Pb)-Sr-Ca-Cu-O targets of various stoichiometries, and subsequently annealed in air at high temperatures. The influence of the initial Pb content, annealing conditions, as well as the substrate material on the growth of the 110-K phase was investigated. We found that the films, fully superconducting above 100 K could be reproducibly fabricated on various dielectric substrates from Pb-rich targets by optimizing annealing conditions for each initial Pb/Bi ratio. Heavy Pb doping considerably accelerated formation of the 110-K phase, reducing the film annealing time to less than 1 h. Films containing, according to the x-ray measurement, more than 90% of the 110-K phase were obtained on MgO substrates, after sputtering from the Bi{sub 2}Pb{sub 2.5}Sr{sub 2}Ca{sub 2.15}Cu{sub 3.3}O{sub {ital x}} target and annealing in air for 1 h at 870 {degree}C. The films were {ital c}-axis oriented, with 4.5-K-wide superconducting transition, and zero resistivity at 106 K. Their critical current density was 2 {times} 10{sup 2} A/cm{sup 2} at 90 K, and above 10{sup 4} A/cm{sup 2} below 60 K. The growth of the 110-K phase on epitaxial substrates, such as CaNdAlO{sub 4} and SrTiO{sub 3}, was considerably deteriorated, and the presence of the 80- and 10-K phases was detected. Nevertheless, the best films deposited on these substrates were fully superconducting at 104 K and exhibited critical current densities above 2 {times} 10{sup 5} A/cm{sup 2} below 60 K{minus}one order of magnitude greater than the films deposited on MgO.

• OSTI ID: 5277976
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 70:6; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ANNEALING
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
CRITICAL CURRENT
CURRENTS
DOPED MATERIALS
ELECTRIC CURRENTS
FABRICATION
FILMS
HEAT TREATMENTS
HIGH-TC SUPERCONDUCTORS
LEAD ADDITIONS
LEAD ALLOYS
MATERIALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SPUTTERING
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE