Strongly enhanced flux pinning by high-energy proton irradiation of a Tl2Ca2Ba2Cu3Oy single crystal.

Flux creep data are reported which clearly demonstrate a dramatic enhancement in the pinning potential for magnetic vortices (fluxoids) in a Tl2Ca2Ba2Cu3Oy single crystal upon irradiation with 4.5 MeV protons. The creep rate is markedly reduced between 5 and 80 K, and the effective pinning potential is quadrupled from ≊100 to ≊400 meV at 20 K in a field of 50 mT. This stronger pinning enhances the magnetization hysteresis and hence the inferred low-field critical current density by a factor of 5 at 40 K. [ABSTRACT FROM AUTHOR]