Publications Details
Stoichiometry and irradiation effects in melt grown Tl-Ca-Ba-Cu-O single crystals
Melt-grown crystals in the Tl-Ca-Ba-Cu-O system with the same structure type can have substantial differences in the superconducting transition, both in width and onset temperature. These differences are attributed to stoichiometry variations arising from cation site substitution. Magnetization and electrical resistivity data are presented which emphasize the extreme sensitivity of the superconductivity to the exact stoichiometry in this system. High quality single crystals exhibit large flux creep due to a weak pinning potential for magnetic flux lines. Flux pinning and thus the critical current density are shown to be significantly enhanced by irradiation with high-energy protons or neutrons. © 1991.