Construction of the Quasi‐ternary Phase Diagram in the NdO_1.5‐BaO‐CuOx System in an Air Atmosphere: Part I, Equilibrium Tie Lines in the Nd_1+xBa_2−xCu₃O_6+δ Solid Solution and Liquid Region

Abstract

Quasi-ternary phase diagrams of the NdO 1.5 -BaO-CuO x system near the CuO x corner have been constructed near the peritectic temperature in air of the Nd 1+x Ba 2−x Cu 3 O 6+␦ (Nd123) solid-solution phase. Liquidus curves were determined by measuring the temperature dependences of the neodymium, barium, and copper solubilities in Nd-BaCu-O solutions with different BaO:CuO ratios. Solidus line compositions and equilibrium tie lines were determined by analyzing the compositions of the Nd123 solid solution equilibrated with the melt by quenching samples held isothermally. Based on the tie-line features in the Nd123-andliquid two-phase field, the Nd123 solid solution with the smaller substitution content was observed to be equilibrated with the solution melt with a higher BaO:CuO ratio, even in an air atmosphere. Nd123 crystal with a substitution content of ∼0.02 could be formed from the solution with the BaO:CuO ratio of ≥0.75, which resulted in higher critical superconducting transition temperatures.

Growth and Structural Characterization of Needlelike Metastable Crystals in the Nd−Ba−Cu−(Al)−O System

“…The crystal structure of the needles is quite different from the one determined by Stalik for Nd-422: a new phase has been produced. In fact, in the Nd−Ba−Cu−O ternary phase diagram, only two ternary oxides, Nd-123 and Nd-422, are described. , Both phases are the ideal end of wide solid solutions. In particular, Nd-422 forms solid solutions composed of Nd 4 - 2 x Ba 2+2 x Cu 2 - x O 10 - 2 x whose space group is P 4/ mbm.…”

Progress in Buffer-Supported Seeding Architectures for Reliable Epitaxial Growth of REBa2Cu3O7−δ Bulk Cryomagnets with Superior Properties

“…On the basis of this perception, the film thermal stability in growing NdBCO/Ag bulks can be strengthened via wetting modification. Similar to an atmosphere with a low oxygen partial pressure, the Ba-rich constitution corresponds to lower Nd solubility in liquid, 63 which possesses a lower wetting ability to the NdBCO film. Thus, the change from normal to Ba-rich constitution results in a smaller contact area between the buffer pellet and the film, as shown in Figure 14.…”

Crystallization Mechanisms of High Critical Temperature Superconductors

“…For the purpose of fabricating a crystal of Nd-123 crystals through melt processing, quasi-ternary phase diagrams of the NdO 1.5 -BaO-CuO x system at the temperatures near the T p of the Nd-123 phase were reported [41,42]. Figure 30.5(A) and (B) show the quasi-ternary phase diagrams of the NdO 1.5 -BaO-CuO x system near the CuO x corner near the T p temperatures (1073 C and 1030 C) in the air atmosphere [41]. As the temperature decreases, the two-phase field of the "Nd-123 þ liquid" becomes large.…”