The magnetic field dependence of transport critical current density (Jct(H)) was measured at 77 K for Bi1.84Pb0.34Sr2.03Ca1.9Cu3.06Oy granular superconductors with Jct(0) of 3814 and 7170 A/cm2. From the initial magnetization curve, the lower critical field (Hcl) of the grain was evaluated to be about 100 Oe in all samples. Intergranular pinning potential (U0gb) was evaluated from the time decay of remanent magnetization after a magnetic field of 50 Oe, which was lower than the Hcl, was applied at 77 K. The values of U0gb were 0.8 and 1.6 eV for the two samples, respectively. The Jct(0) was almost proportional to the U0gb.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering