Abstract: | We present a reliable method for growing single crystals of Y1−xPrxBa2Cu3O7−δ high-Tc superconductors in ZrO2 crucibles. This method results in crystals with greatly improved superconducting properties compared to crystals grown with the previously reported methods which use Al2O3 crucibles. We describe techniques for crystal growth in both Al2O3 and ZrO2 crucibles using an excess of BaCo3 and CuO as the flux. The crystals were characterized by means of DC magnetic-susceptibility measurements, electrical-resistivity measurements, and electron microprobe analysis. The effects of Al contamination on the conditions for crystal growth and on the superconducting properties of the crystals are found to be quite significant. |