Lower critical field and reversible magnetization of (Bi, Pb)2Sr2Ca2Cu3Ox superconducting whiskers

✍ Scribed by Ichiro Matsubara; Ryoji Funahashi; Kazuo Ueno; Hiroshi Yamashita; Tomoji Kawai

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 426 KB
• Volume: 256
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00599-4

✦ Synopsis

Magnetization measurements have been carried out on Pb doped Bi2SrzCa2Cu30 ~ (Bi-2223) whiskers with the applied field parallel to the c-axis. The temperature dependence of the first flux penetration field Hp can be approximated by Hp(T) = Hp(0)[1 -(T/Tc) 2 ] in the region T> 50 K, while it increases upward with decreasing temperature especially at T< 30 K due to the surface barrier. The value Hp = Hca(0) = 135 G is obtained by fitting the experimental data for T> 50 K. The penetration depth Aab(0)= 2450 /k, Ginzburg-Landau parameter K = 84, and thermodynamic critical field He(0) = 3300 G have been calculated from the Hc~(0) value together with the upper critical field and coherence length. The penetration depth has also been evaluated from the reversible magnetization curves. A~ -2 is a linear function of the temperature near To.