Speaker
Description
GdBCO bulk superconductors possess unique superconducting properties, making them highly attractive for various practical applications [1]. They are typically prepared using the top-seeded melt growth (TSMG) process [2], in which a single-crystal seed is placed at the centre of the top surface of the pellet. Recently, a new method – single-direction melt growth (SDMG) – has been introduced [3]. In this approach, the single-grain bulk sample grows from a large seed on which the pressed pellet is placed, offering several advantages compared to TSMG-grown samples.
In this study, we prepared a GdBCO single-grain bulk superconductor with a nominal composition of $70$ wt$\%$ GdBa$_2$Cu$_3$O$_x$ (Gd123) + $30$ wt$\%$ Gd$_2$BaCuO$_5$ (Gd211) + $10$ wt$\%$ Ag$_2$O + $0.945$ wt$\%$ BaCeO$_3$ using the SDMG process. Macroscopic superconducting properties, including the trapped magnetic field and levitation force, were measured at liquid nitrogen temperature ($77.3$ K). The critical transition temperature, $T_c$, transition width, $\Delta T_c$ and $J_c(B)$ dependencies at $77$ K and $40$ K were evaluated at different positions within the bulk sample. Additionally, a detailed microstructural analysis, focusing on the size and volume fraction of Gd$211$ particles, was conducted in relation to the measured superconducting properties. The benefits of the GdBCO bulk samples prepared using the SDMG process, in contrast to those produced by TSMG, are discussed.
Acknowledgements
This work was supported by the Slovak Grant Agency (APVV-17-0625, APVV-21-0387), VEGA (No. 2/0044/19, No. 2/0094/22), and the European Union NextGenerationEU through the Recovery and Resilience plan for Slovakia under project No. 09I03-03-V04-00303.
References
[1] J. H. Durrell et al., “Bulk superconductors: a roadmap to applications,” Superconductor Science and Technology, vol. 31, no. 10. IOP Publishing, p. 103501, Sep. 11, 2018. https://doi.org/10.1088/1361-6668/aad7ce
[2] D. K. Namburi et al., “THE PROCESSING AND PROPERTIES OF BULK (RE)BCO HIGH TEMPERATURE SUPERCONDUCTORS: CURRENT STATUS AND FUTURE PERSPECTIVES,” Superconductor Science and Technology. IOP Publishing, Jan. 21, 2021. https://doi.org/10.1088/1361-6668/abde88
[3] T. Motoki et al., “Development of homogeneous and high-performance REBCO bulks with various shapes by the single-direction melt growth (SDMG) method,” Superconductor Science and Technology, vol. 35, no. 9. IOP Publishing, p. 094003, Jul. 21, 2022. https://doi.org/10.1088/1361-6668/ac811e
