Effects of residual carbon on phase formation of TlBa2Can−1CunOy (n=3 and 4) superconductors

• Published in: Physica. C, Superconductivity Vol. 370; no. 3; pp. 205 - 209
• Main Authors: Iyo, A, Ishiura, Y, Tanaka, Y, Badica, P, Tokiwa, K, Watanabe, T, Ihara, H
• Format: Journal Article
• Language: English
• Published: 01-05-2002
• ISSN: 0921-4534
• DOI: 10.1016/S0921-4534(01)00927-3

The effects of residual C in precursors on phase formation of single Tl-O layer superconductors of TlBa2Can-1CunOy (n=3 and 4) have been investigated. The samples were prepared from Tl2O3 and precursors of Ba2Can-1CunO2n+1+d(Cx) (n=3 and 4) with various residual C contents (x=0.02-0.19). Even a small amount of C promotes the formation of double Tl-O layer phases of Tl2Ba2Can-1CunOy (n=3 and 4). Using the C reduced precursor (x=0.02), a TlBa2Ca2Cu3Oy phase is synthesized directly in a Ag-sheathed tape without such elements as Pb, Bi and Sr. 10 refs.