Upper and Lower Critical Fields of High-Tc Tl-Ba-Ca-Cu-O System
- 1 September 1988
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 27 (9A) , L1631
- https://doi.org/10.1143/jjap.27.l1631
Abstract
Magnetization and electrical resistance are measured on sintered Tl-Ba-Ca-Cu-O samples whose compositions are Tl:Ba:Ca:Cu=2:2:2:3, 2:2:3:3 and 2:2:1:2. The superconducting transition temperature T c is 114 K for the 2:2:2:3 and 2:2:3:3 samples and is 98 K for the 2:2:1:2 sample. The difference in T c comes from the numbers of perovskite-like layers between Tl2O2 layers. The upper critical fields H c2 of the 2:2:2:3 sample increases linearly just below T c (-(dH c1/dT) T c =13 kOe/K) and the lower critical field H c1 increases monotonically with decreasing temperature down to 4.2 K (-(dH c1/dT) T c =4.5 Oe/K and H c1(0)=500 Oe). From the results, some superconducting parameters such as ξ, κ, λ and H c are calculated.Keywords
This publication has 4 references indexed in Scilit:
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