Disclosed is a method for producing a superconductor of the R-Ba-Cu-O system which comprises of selecting an insulating material of the formula RBa{sub x}Cu{sub y}O{sub z} where R is selected from the group consisting of Y, La, Pr, Nd, Sm, Eu, Gd, Ho, Er, Tm, and Lu, and where x ranges from about 1.7 to about 2.3, y ranges from about 2.7 to about 3.3 and z ranges from about 5.0 to about 6.99, and halogenating said material with a halogen selected from the group consisting of chlorine, bromine, iodine, and mixtures thereof, while maintaining said material at a temperature ranging from about 160 to about 440{degrees}C, for a period of time sufficient to cause incorporation of said halogen into said material. Also, disclosed are the materials produced by the method and articles of manufacture incorporating said materials as electronic circuitry components.

A method for producing homogenous single crystal III--V ternary alloys of high crystal perfection using a floating crucible system in which the outer crucible holds a ternary alloy of the composition desired to be produced in the crystal and an inner floating crucible having a narrow, melt-passing channel in its bottom wall holds a small quantity of melt of a pseudo-binary liquidus composition which would freeze into the desired crystal composition. The alloy of the floating crucible is maintained at a predetermined lower temperature than the alloy of the outer crucible, and a single crystal of the desired homogeneous alloy is pulled out of the floating crucible melt, as melt from the outer crucible flows into a bottom channel of the floating crucible at a rate that corresponds to the rate of growth of the crystal.