Barium cerate (BaCeO3) is one of the preferred additions to bulk YBa2Cu3O7 single-grain superconductors to inhibit the growth of Y2BaCuO5 particles. The present paper investigates synthesis of very fine barium cerate powder and its use in YBa2Cu3O7 bulk superconductor growth. The crystalline barium cerate was synthesized by oxalate co-precipitation from barium and cerium nitrates. X-ray diffraction in air and vacuum was performed to understand the formation of barium cerate as well as to determinate its crystal structure. Size and shape of BaCeO3 particles were studied by scanning electron microscopy. The BaCeO3 was used to grow YBa2Cu3O7 bulk superconductor. Microstructure of prepared YBa2Cu3O7 crystal shows that the barium cerate in the final product is very fine and uniformly distributed throughout the whole YBa2Cu3O7 crystal.

Crystalline barium cerate was synthesized by oxalate coprecipitation from nitrates of barium and cerium [1]. The oxalate precursor prepared by chemical methods was calcined at different temperatures up to 950°C. The barium cerate was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). X-ray diffraction investigation enables the determination of the phases that originate at different stages of synthesis and the crystal structure of final barium cerate, as well. From XRD patterns the average size of coherent regions was estimated by using Halder-Wagner method [2]. Both size and shape of crystallites were also studied by scanning electron microscopy. It was found that crystallites of barium cerate arise within the initial particles of the oxalate precursor.