Flux Pinning in Melt-Grown NdBa₂Cu₃O_y and SmBa₂Cu₃O_y Superconductors

Abstract

REBa2Cu3O y superconductors with rare earth (RE) ions with large radii (RE: La, Nd, Sm) exhibit relatively low T c due to the presence of RE-Ba solid solution. We have found that this solid solution can be suppressed if these superconductors are melt processed in a reduced oxygen atmosphere. We have also found that critical current densities of these superconductors are higher than those of melt processed YBa2Cu3O y with fine Y2BaCuO5 inclusions in a high field region. The irreversibility line was also shifted toward the higher H-T region. We believe that flux pinning in these superconductors is ascribable to a finely distributed RE(Ba1- x , RE x )2Cu3O y phase in a good superconductive matrix.

Thermodynamic Properties of Nd1+xBa2–x­Cu3Oy Compounds and Their Application for Optimizing the Synthesis of Superconducting Materials

“…The results of experiments on the determination of the calorimetric reaction enthalpies [reactions (1)- (5)] are shown in Tables 1 and 2, where the values of enthalpies are the average of five measurements. The uncertainties quoted in this work refer to a 95 % confidence limit.…”

“…[1][2][3][4] Among such compounds, NdBa 2 Cu 3 O y (Nd-123) is the most promising because of its high superconducting transition temperature and enhanced critical current density. [5][6][7] Contrary to YBa 2 Cu 3 O y (Y-123), the Nd 1+x Ba 2-x Cu 3 O y phase reveals a region of homogeneity, and the superconducting properties of the material deteriorate sharply when barium is replaced by neodymium. [8] The region of homogeneity stretches from x = 0 to x = 1 in the Nd 1+x Ba 2-x Cu 3 O y solid solution.…”

Mobilidade de oxigênio intersticial em cerâmicas SmBa2Cu3O7-delta

“…As amostras de SBCO possuem temperatura crítica (T c ) maior que a do YBCO [1,2] e uma solubilidade maior do íon terra rara que no solvente Ba-Cu-O [3], fazendo com que o processo de crescimento seja mais rápido.…”

Oxygen-Uptaking in Nd1.1Ba1.9Cu3Oy Solid Solution Investigated by the Isothermal Resistance Relaxation

“…It is clearly shown that the OCMG (oxygen controlled melt growth) NdBaCuO exhibits a higher irreversibility field and an irreversibility temperature, and that it usually shows improved critical current characteristics at higher fields due to the peak effect in the magnetization curve [1,2]. In addition, the growth rate of NdBaCuO is faster than YBCO [3,4].…”

“…As in YBCO, an oxygen-uptaking process at low temperatures is necessary for good performance. Murakami et al [1,2] observed that, different from MTG YBCO, the oxygen-uptaking at 300-250 C could still strongly improve the superconducting properties for OCMG NdBaCuO. Erb et al [5] also found that the oxygenation temperature, at which the maximum transition temperature can be obtained, is lower for NdBCO than that for YBCO.…”