|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1996 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1995 : ¥1,700,000 (Direct Cost : ¥1,700,000)
1. Oxygen Analysis
Using the device in our laboratory, the analytical procedures of oxygen content in neodymium and praseodymium were studied as a function of flux and temperature. On the basis of the experimental results, optimum conditions for accurate oxygen analysis were obtained at 2873 K with tin concentrations above 0.3 mole fraction for neodymium and above 0.5 mole fraction in the case of praseodymium.
2. Oxygen Solubility in Solid Neodymium and Praseodymium
The oxygen solubility in solid neodymium and praseodymium were determined by diffusion couple method and solid state erectrotransport. Oxygen solubilities in solid neodymium were 0.0774 mass%(1023K), 0.0997 mass% (1073 K), 0.122 mass% (1123 K), 0.136 mass% (1173 K), 0.148 mass% (1223 K) and 0.161 mass% (1248 K) respectively. By the X-ray diffraction analysis, NdO was identified as the equilibrium oxide phase with solid neodymium in the whole temperature range of these experiments. On the other hand, solubility of the oxygen in praseodymium was 0.0595 mass% at 1113 K.
3. Oxygen Solubility in Liquid Neodymium
Solubility of oxygen in liquid neodymium was measured by equilibrating the metallic melt with the neodymium oxide (Nd_2O_3) in a molybdenum crucible sealed in quartz capsule. Oxygen solubilities of 0.182 mass% (1373 K), 0.296 mass% (1473 K), and 1.46 mass% (1773 K) were obtained respectively. By the X-ray diffraction analysis, Nd_2O_3 was identified as the equilibrium oxide phase with liquid neodymium at 1473 K.