Initial composition dependence of the critical current density in filamentary NSG123 superconductors

✍ Scribed by Y. Ikebe; E. Ban; Y. Matsuoka; G. Nishijima; K. Watanabe

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 187 KB
• Volume: 468
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2008.05.077

✦ Synopsis

The effect of the starting composition on the superconducting properties for ternary system (Nd, Sm, Gd)-Ba-Cu-O filaments was systematically investigated. The filaments with the composition of (Nd 0.33 ,Sm 0.33 ,Gd 0.33 ) 1.18 Ba 2.12 Cu 3.09 O y (sample A), (Nd 0.50 ,Sm 0.25 ,Gd 0.25 ) 1.18 Ba 2.12 Cu 3.09 O y (sample B), (Nd 0.25 ,Sm 0.50 ,Gd 0.25 ) 1.18 Ba 2.12 Cu 3.09 O y (sample C) and (Nd 0.25 ,Sm 0.25 ,Gd 0.50 ) 1.18 Ba 2.12 Cu 3.09 O y (sample D) were prepared by a solution spinning method. All samples partially melted at temperature range of 1030-1080 °C in flowing 0.1% O 2 + Ar exhibited J c value higher than 10 4 A/cm 2 at 77.3 K and self-field. Among these samples, the best transport J c value of 7.2 Â 10 4 A/cm 2 was attained in sample B with Nd-rich composition. The field dependence of transport J c value was also examined at various temperatures between 77.3 K and 90 K in applied magnetic fields up to 17 T. In the case of samples A, the J c value gradually decreased with increasing the applied magnetic field, and the J c value of 2.4 Â 10 3 A/cm 2 at 77.3 K was maintained up to high magnetic fields of 17 T. On the contrary, the J c value of sample B decreased with increasing the applied magnetic field and the superconductivity disappeared at about 15 T. It was found that the three element ratio in NSG123 contributed to flux pinning in a different manner and affected in J c behavior in magnetic field.