Formation of anisotropic Tl-1212, Tl-2212, Tl-1223 and Tl-2223 particles using aerosol flow reacted powders

Technical Report · Sat Dec 31 04:00:00 EST 1994

DOI:https://doi.org/10.2172/28370· OSTI ID:28370

Paranthaman, M; Goyal, A; Heatherly, D E; Kroeger, D M

Highly anisotropic particles of Tl-1212, Tl-2212, Tl-1223 and Tl-2223 superconductors were grown. The Tl-free precursor powders with the compositions Ba{sub 1}Ca{sub 2}Cu{sub 3}Ag{sub 0.37}O{sub 6} and Ba{sub 2}Ca{sub 2}Cu{sub 3}Ag{sub 0.37}O{sub 7} were prepared using an aerosol flow reactor. These precursor powders were then post-annealed in 0.1 atm oxygen at 700 C for 4h to reduce the carbon present and mixed with Tl{sub 2}O{sub 3} (typical composition of Tl{sub x}; x = 0.6--1.0). The Tl-containing powders were heated in sealed gold tubes between 650--890 C for various times. X-ray diffraction showed that the Tl-2212 and Tl-2223 phases were stable over a wide range of temperatures. Scanning electron microscopy showed evidence for the presence of high aspect-ratio particles. These highly anisotropic particles may be of interest for the preparation of powder-in-tube and other powder deposited conductors, for current leads, and for grain alignment studies.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); Oak Ridge Inst. for Science and Education, TN (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 28370
• Report Number(s): CONF-941013--28; ON: DE95007400
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CALCIUM OXIDES
CHEMICAL REACTORS
COPPER OXIDES
EXPERIMENTAL DATA
FABRICATION
GRAIN SIZE
HIGH-TC SUPERCONDUCTORS
MICROSTRUCTURE
PARTICLE SIZE
PHASE STUDIES
SILVER OXIDES
THALLIUM OXIDES