The effect of platinum and excess 211 phase on the loss of the liquid phase in melt textured YBa2Cu3O7-x

Platinum is an important additive in YBa2Cu3O7-x (123) powders for melt pro cessing and growth of large oriented crystals, but its role in liquid loss during the growth cycle is poorly understood. A series of experiments were conducted to determine how platinum effects liquid loss, and to study the s olubility limit of platinum in 123. Both atomically mixed and solid state p latinum sources were compared. Crystals were grown on a non reactive setter so that liquid loss could be clearly distinguished by. weight from reactio n products with the setter. Based on weight loss studies there was little d ifference between atomically added platinum and by adding platinum powder t o the 123 powder. In samples with no excess Y2BaCuO5 (211) weight loss due to liquid loss was at a minimum of 3.8 percent with 0.3 weight percent plat inum content. Examination with an electron microprobe reveals different mic rostructures for the two different methods of platinum additions.