Sintering process and characterization of the SmBaCuO/Al composite

• Published in: Physica. C, Superconductivity Superconductivity, 2023-04, Vol.607, p.1354243, Article 1354243
• Main Authors: Nunes, L.G.S., Passos, C.A.C., Orlando, M.T.D., Chagas, J.V.S., Salustre, M.G.de M., Galvão, E.S.
• Format: Article
• Language: English
• Subjects: Composite; High-Tc; Microhardness; Sintering process; Sm-123; Superconductivity
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2023.1354243

•The (1-x)SmBa2Cu3O7-δ/(x)Al composite was prepared by solid state reaction.•The aim was combined mechanical and superconducting proprieties.•The composites have a critical temperature Tc = 90 K, similar to that found in Sm-123 ceramics, and a diamagnetic signal proportional to the volumetric fraction of the ceramics.•The aluminum addition has improved the tenacity of Sm-123 ceramic and it did not affect their superconducting properties. The electrical, mechanical, and magnetic properties of superconducting ceramics have been investigated targeting technological applications. However, there are still technological challenges imposed to superconducting ceramics due to the requirement of cryogenic temperatures and the correlations with electrical, magnetic, mechanical, and/or thermal stresses aiming at the applicability of these superconductors. Taking this scenario into consideration, we describe the fabrication process of SmBa2Cu3O7-δ/Aluminum composites. Samples of SmBa2Cu3O7-δ (Sm-123) ceramic, aluminum (Al) and (1-x)SmBa2Cu3O7-δ/(x)Al (x = 40, 50 and 60 wt%) composites were prepared by the solid-state reaction method. All samples were characterized by X-ray diffraction, magnetic susceptibility, scanning electron microscopy, relative density, and Vickers microhardness measurements. The results of microstructural analysis indicated that the addition of Al particles did not alter the crystal structure of the Sm-123 phase. Furthermore, ac magnetic susceptibility measurements of the samples revealed that the onset of the transition to the superconducting state of the composites are Tc ≈ 92K. However, the superconducting transitions of the composite samples showed a broadening as a result of the proximity and disorder effect. Energy dispersive spectrometry (EDS) analysis and elemental distribution maps of the composite samples indicated that Al nanoparticles precipitated at the grain boundaries of Sm-123 ceramics. Finally, the Vickers microhardness values decreased with the addition of Al. Since aluminum resides at the grain boundaries, this improved the toughness of Sm-123 ceramics and did not affect its superconducting properties.