Excellent Critical Current Performance Observed inSingle Crystals of Bi-based Cuprates Grown by a NewlyDeveloped Laser Floating Zone Furnace

摘要

We have designed and developed a new floating zone(FZ)furnace with extremely high temperature gradient, which is achieved by aYAG(Nd) laser light and optical lenses(NEC-FZ-S-0101). Crystal boulesof Bi-based superconductors, such as Bi2212, Bi(Pb)2212, and Bi2223,were grown using this newly developed FZ furnace. The Bi2212 singlecrystals with excellent crystallinity were obtained through the crystalgrowth at a high rate of 1.9 mm/h by using the new FZ furnace.Bi(Pb)2212 single crystals were also grown and they exhibited enhancedflux pinning properties, while their analyzed chemical composition wasalmost identical to that of crystals grown by the conventional method. Inaddition, Bi2223 single crystals were successfully obtained at highergrowth rate up to 0.15 mm/h by using the same furnace.