Processing of large Y1Ba2Cu3O7-x single domains for current-limiting applications

Bulk-textured YBa2Cu3O7-x Single domains could be used for current-limiting applications by cutting and assembling long meanders, which would be submi tted to network electric fields before using a breaker to interrupt a fault current. For that purpose, large YBaCuO single domains up to 93 mm in diam eter can be isothermally grown by using a standard melt texturing growth (M TG) process with a SmBaCuO seed. The essential parameters that have to be c ontrolled in order to reach this size are the temperature growth window, th e substrate reactivity and the temperature homogeneity in the sample. Stand ard 45 mm diameter single domains show excellent superconducting properties , such as J(c) above 10(5) A cm(-2) and a homogeneous superconducting-to-no rmal transition at 91.8 K for 20 cm long conductors cut in these pellets. T hese measurements demonstrate the long -range homogeneity of single domains regarding T-c and J(c). Nevertheless the high J(c) values lead to a too la rge a dissipation in the normal state at T = 77 K. Different methods to red uce the critical current density are described in order to fulfill the cond itions for a safe recovery of the material after undergoing a magnetotherma l transition.