Abstract
cw laser annealing has been applied to synthesize the metastable A15 superconductors, Nb 3 Al and Nb 3 Si. Qualitative agreement with the equilibrium phase diagrams have been obtained for the Nb-Al system. Laser annealing permits the high-temperature A15 phase to be fast quenched to room temperature without decomposition. Subsequent use of multiple low-temperature laser scans raises the superconducting transition temperature, probably by improving the atomic order. For the Nb-Si system, a single-phase nonstoichiometric A15 structure is formed from the amorphous phase upon laser annealing.