Preparation of 147pm Metal and the Determination of the Melting Point and Phase Transformation Temperatures

摘要

The promethium metal used in the determination of the melting point and phase transformation tempera¬tures was prepared by reduction of promethium oxide with thorium metal at 1600CC and distilling the promethium metal into a quartz dome. The melting point and phase transformation temperatures of promethium metal were found to be 1042 ± 5°C and 890 ± 5°C, respectively. The ratio for the heat of the high-temperature transformation to the heat of fusion was determined to be 0.415.