The solubility of oxygen in solid and liquid neodymium, were measured by the solid state electrotransport and metal-oxide equilibrium methods, are determined as follows: Solubility in solid neodymium; log (CO /mass %) Nd (α) = -1760 (± 20)T-1/ K-1) + 0.65 (± 0.02) (1,023 ∼ 1,123 K) log (CO /mass %) Nd (β) = -1850 (± 30)T-1/ K-1) + 0.70 (± 0.03) (1,173 ∼ 1,248 K) Solubility in liquid neodymium; log (CO/mass %) Nd (l) = -5580 (± 30)T-1/ K-1) + 3.30 (± 0.04) (1,373 ∼ 1,773 K) NdO was identified by the X-ray diffraction analysis as the oxide phase in equilibrium with neodymium from 1,023 to 1,248 K and Nd2O3 was identified as the oxide phase in equilibrium with neodymium from 1,373 to 1,773 K.
