Abstract
The bulk sample simply produced by pressing calcined superconductor powder shows no superconductive properties. Laser scan transforms however such non-superconducting bulk material into superconductive one partially along the scanned area. The goal of this study is to make superconductive circuits on the surface of the(Bi 2223 system)non-superconductive bulk by scanning focused laser beam as designed. This paper reports the effect of 150W CO2 laser irradiation on the superconducting property of the bulk by changing the following conditions: beam scan speed (bss), beam scan times(bst)and assist gas pressure(agp).The best result of Tc(end)=66.5 K was obtained when the laser irradiation was performed with bss=10 mm/min, bst=1 stroke and agp=49 kPa. Superconductive crystals were grown at the laser irradiated area with depth of-300μm. The crystals were oriented to the same direction of the beam scan.
