Crystallization of CoO-Li2O-SiO2 Glass under Microgravity Produced by Sounding Rocket (TR-IA #2)

Abstract

A binary Li2O-SiO2 glass containing CoO (1 mol%) was melted in an image furnace under microgravity aboard the rocket (TR-IA #2) and the super cooling phenomena and crystallization process were observed. The sample was fixed at the focus point with the supporting base and connected with thermocouple for measuring the supercooling and crystallization temperature (1201°C). Supercooling and exothermic phenomenon by crystallization were observed during the cooling process and supercooling temperature from melting temperature was 57°C. Crystallization occurred, with exothermic change and initial crystallization took place at the contact point of molten glass and supporting base and its crystal growth speed was 0.26cm/sec under microgravity. According to results of X-ray diffraction analysis, crystals was identified as Li2SiO3.