Nb 3 Al and Nb 3 (Al,Ge) tapes with excellent superconducting properties were fabricated by the laser beam irradiation method. Nb-25 at %Al and Nb-20 at % Al-5 at % Ge tapes were prepared by the powder metallurgy process. Continuous CO 2 laser beam irradiation was carried out on the tape surface in an argon gas atmosphere at 1-13m/min, velocities. Beam power was 0.3-4kW and beam diameter at the tape surface was 0.5-3mm. As the power density was high and irradiation time was short, the tape could be heated and cooled much faster than a tape that was heat treated by the conventional method. The results were fine grain structure and large J c values at high magnetic fields. T c for an as-irradiated tape was 16-18K. This T c increased by ∼2K by the subsequent annealings at 700°C for 100 hours. The maximum T c (onset) values obtained were 18.6K for the Nb 3 Al tape and 20.1K for the Nb 3 (Al,Ge) tape, which indicated that stoichiometric compounds could be formed by laser beam irradiation. Annealed tapes, after the irradiation, showed excellent J c values, especially at high magnetic fields. J c values over 2×10 4 A/cm ² at 23 Tesla were obtained for both Nb 3 Al and Nb 3 (Al,Ge) tapes. These values are much larger than those obtained by conventional heat treatment. J c values of as-irradiated tapes at high fields were smaller than those for annealed tapes, due to the lower T c and, hence, lower H c2 . The large J c values, as well as easy scale-up procedure, indicate that the laser irradiation method is promising for the fabrication of advanced superconductors, e.g. Nb 3 Al and Nb 3 (Al,Ge) capable of generating fields over 20 Tesla.

#	Concept	H-Index	Publications	Citations
1	Engineering	2	2	43
2	Applied Physics	2	2	43
3	Materials Science	2	2	43
4	Physics	2	2	43
5	Materials Engineering	1	1	12

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