Bi-2212 superconducting single crystals were grown by the travelling solvent floating zone method at different oxygen ambient pressures. Electron probe micro-analysis showed a systematic increase of the Sr/Ca ratio in the as-grown crystals with increasing oxygen ambient pressure and a maximal superconducting transition temperature of Tc~onset= 95 K, and ziT= 1.5 K was obtained for crystals grown at an oxygen ambient pressure of 200 kPa. Thermogravimetric and post-annealing experiments in air at 500 and 800°Chave shown that the oxygen content and the Tconset values in the crystal do not depend only on the annealing temperature, but also on its chemical composition. The in-field current density J~measured at 5 K on crystals grown at 200 kPa oxygen ambient pressure was considerably smaller than that of crystals grown in air.

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