Melting and Solidification of Y-Ba-Cu-O Ceramics in Microgravity by Utilizing TR-IA Sounding Rocket

Melting and solidification phenomena of polycrystalline YBa2Cu3Ox bulk sample in microgravity were studied by utilizing TR-IA sounding rocket. Microgravitational experiment and the terrestrial one were carried out by using HTF apparatus to improve the fundamental understanding of these phenomena in microgravity. Video image observation reveals that oxygen gas bubbles were released at the liquid surface of the specimen more frequently in the terrestrial than in microgravity. Macroscopically, major difference between both samples is confirmed in the molten region. This can be explained by the difference in the conditions of thermal conduction and heat flow between both environments. No superconductivity is observed in both samples at the “as melt-solidified” state. After the post annealing, the μG sample shows steeper superconducting transition than the terrestrial one.