In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 17, No. 6 ( 2002-06), p. 1266-1275
Abstract:
YBa 2 Cu 3 O 7− y (Y123) and Nd 1+ x Ba 2− x Cu 3 O 7− y (Nd123) films were deposited by the metalorganic deposition method, and the growth mechanism of these films was investigated by high-resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. The Y123 and Nd123 films were prepared by spin-coating LaAlO 3 (001) and SrTiO 3 (STO) (001) substrates, respectively, with solutions including trifluoroacetates. Then, the samples were heat treated at 673 K in a humid O 2 gas flow to form amorphous precursor films. Finally, the precursor films were heated at higher temperatures for 0–30 min in a humid Ar/O 2 gas flow and cooled rapidly from those annealing temperatures. It was found that CuO crystals with a size of 10–20 nm are segregated in the Y123 and Nd123 amorphous precursor films. In the Y123 quenched film prepared by cooling the precursor film rapidly after the heat-treatment at 1048 K for 30 min, a polycrystalline film including Y 2 Cu 2 O 5 , BaF 2 , and CuO crystals was found to be generated on the c -axis-oriented Y123 film. In contrast, in the Nd123 quenched films, (NdBa) 2 CuO 4 (Nd201) phase was found to be formed first on the surface of the STO substrate. In conclusion, the c -axis-oriented Y123 film is formed by diffusion and reaction of Y 2 Cu 2 O 5 , BaF 2 , and CuO crystals, and the Nd201 phase reacts with BaF 2 and CuO crystals in a humid atmosphere to form a c -axis-oriented Nd123 film.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/JMR.2002.0190
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2002
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8
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