The effect of post-annealing on laser-deposited superconducting Bi--Sr--Ca--Cu--O thin films

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1993.2162· OSTI ID:6252917

Kung, P J; Wu, X D; Muenchausen, R E; Salazar, K V; Foltyn, S R; Peterson, D E; Garcia, A R ^[1]

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1. Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Superconducting Bi--Sr--Ca--Cu--O thin films were obtained from post-annealing partially crystallized and amorphous films grown on MgO (100) by pulsed laser deposition. The substrate temperature investigated was in the range of 350--750 [degree]C, over a range of pressure 0.1 to 100 mTorr. The as-deposited films were annealed in 7.5 vol% O[sub 2]/Ar or in air at 800--865 [degree]C from several minutes to a few hours. Unlike the pure Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8+[delta]] (2212) phase ([ital T][sub [ital c]]=80 K) which is easily formed after a long continuous period of post-annealing at temperature below 830 [degree]C, the formation of (Bi,Pb)[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 10+[delta]] (2223) phase from the as-deposited amorphous films requires repetitive annealing cycles of short duration in air at 850 [degree]C to simultaneously achieve good crystal quality, small surface roughness, and sharp diamagnetic transition ([ital T][sub [ital c]]=110 K). After annealing, the temperature is lowered down to [similar to]650 [degree]C by quenching in air and then a slow-cooling step is employed. This procedure was found to enhance the volume fraction of the 2223 phase as compared with a direct slow-cooling process. The trade-off between annealing temperature and time was observed to affect the phase formation and the smoothness of the annealed films. To optimize the post-annealing conditions, Rutherford backscattering spectrometry, x-ray diffraction, and scanning electron microscopy were systematically used to examine the composition, structure, and morphology of the films, respectively.

• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6252917
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 8:9; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
AIR
ALKALINE EARTH METAL COMPOUNDS
ANNEALING
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
DEPOSITION
ELECTROMAGNETIC RADIATION
FILMS
FLUIDS
GASES
HEAT TREATMENTS
HIGH-TC SUPERCONDUCTORS
LASER RADIATION
OXIDES
OXYGEN COMPOUNDS
PULSES
RADIATIONS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
THIN FILMS
TRANSITION ELEMENT COMPOUNDS