Recrystallization of amorphous and nanocrystalline NdBa{sub 2}Cu{sub 3}O{sub 7{minus}x} and GdBa{sub 2}Cu{sub 3}O{sub 7{minus}x}
- Iowa State Univ. of Science and Technology, Ames, IA (United States). Inst. for Physical Research and Technology
- Ames Lab., IA (United States)
Using a novel melt-spinning technique, we have produced both amorphous and nanocrystalline NdBa{sub 2}Cu{sub 3}O{sub 7-x} and GdBa{sub 2}Cu{sub 3}O{sub 7-x} materials. Samples melt-spun in O{sub 2} consist of nanocrystals with the tetragonal 123 structure while those processed in N{sub 2} show an amorphous matrix with small amounts of crystalline BaCu{sub 2}O{sub 2}, as shown by XRD and TEM studies. The difference is due to the strong dependence of the phase relations on the O{sub 2} partial pressure. Superconductivity can be fully restored by heating above 1000C followed by a 450C anneal in O{sub 2}. High temperature XRD studies show that the 123 phase crystallizes directly from the amorphous matrix below 800C. Poor superconducting properties for sample heated below 1000C are attributed to disorder on the heavy metal sites. 4 figs, 6 refs.
- Research Organization:
- Ames Lab., IA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-82; FG02-90ER45427
- OSTI ID:
- 10116084
- Report Number(s):
- IS-M-722; CONF-920802-47; ON: DE93004469
- Resource Relation:
- Conference: Applied superconductivity conference,Chicago, IL (United States),23-28 Aug 1992; Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
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