Crystal growth of Nd-Ce-Cu-O and 2201 Bi compounds

The paper describes the growth of high-quality plateletlike Bi-based and Nd-based cuprate single crystals of well-defined composition and large size. Nd(2-x)Ce(x)CuO4 crystals within the range of composition (0-0.20) with a size of up to several millimeters were grown via a flux technique using a CuO flux at temperatures between 1100 and 1500 C in a vertical temperature gradient. The sharpest and highest superconducting transition Tc = 21 + 1K was obtained for crystals with a Ce content of 0.14. A similar technique was applied to the more complicated BiO-layered compounds leading, for example, to crystals of a size larger than 1 x 1 cm for the Bi2Sr2CuO(6 + y) (2201) compound. By controlling the growth ambient, the physical properties of these crystals can be changed from semiconducting to metallic or superconducting. The application of this flux technique to the crystal growth of other Bi-based phases in which Cu has been completely replaced by 3d metals is also described. 22 refs