Effect of oxygen partial pressure on the neodymium solubility in BaCuO solvent
1996; Elsevier BV; Volume: 266; Issue: 3-4 Linguagem: Inglês
10.1016/0921-4534(96)00311-5
ISSN1873-2143
AutoresMasaru Nakamura, Makoto Kambara, Takateru Umeda, Yuh Shiohara,
Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoThe neodymium (Nd) solubility in BaCuO solvent with a Ba to Cu ratio of 3 to 5 was investigated under different oxygen partial pressures (P(O2) = 1, 21, 100%). A small amount of the solution was taken out by dipping thermally equilibrated MgO single crystals, and compositions of these specimens stuck with liquid on the MgO, were analyzed by inductively coupled plasma spectrometry (ICP). Sampling the solution for ICP analysis was performed in the temperature range from approximately 1000°C up to 1200°C. The peritectic temperature of NdBa2Cu3O7−δ (Nd123) increased with increasing oxygen partial pressure. The Nd solubility at the peritectic temmperature of Nd123 increased with increasing oxygen partial pressure. The slope of the Nd 123 liquidus lines near the peritectic temperature decreased with increasing oxygen partial pressure. Assuming a regular solution, expressions for the solubility and the enthalpy of dissolution of Nd123 and Nd4Ba2Cu2O10 (Nd422) were derived from classical thermodynamic calculations. The enthalpies of dissolution ΔHdiss for Nd123 and Nd422 decreased with increasing oxygen partial pressure.
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