Speaker
Description
For superconducting magnets and other applications, enhancing the critical current density (Jc) is required. There are several possible approaches for enhancing Jc in REBa2Cu3Oy coated conductors (CCs); one is by introducing and tailoring pinning centers to immobilize vortices. Another is by enhancing the thermodynamic critical field (Hc∝(ξλ)-1) through reducing the penetration depth (λ) and the coherence length (ξ). Previously, we have shown a large enhancement in Jc at not only self-field but also in-field by introducing a high density of incoherent BaHfO3 nanoparticles (BHO NPs) of a tailored size into (Y0.77Gd0.23)Ba2Cu3Oyc ((Y,Gd)123) CCs, which leaves the matrix unaltered with just slightly decreased superconducting properties[1]. Reducing λ and ξ would improve Hc and consequently Jc. If both thermodynamic and pinning optimization routes can be combined, Jc can be dramatically improved.
In this work, we combined the thermodynamic route (decreasing λ and ξ by tuning the carrier density) with our previously developed methods to tailor the size and incorporate high densities of incoherent BHO NPs. We obtained Jc∼150 MA/cm2 at 4.2 K in self-field [2]. Moreover, the remarkably high pinning force in the nanocomposite (Y,Gd)123 CCs reached ~3.17 TN/m3 at 4.2 K and 18 T (H||c). Detailed microstructural and superconducting properties for nanocomposite RE123 CCs will be presented.
References
[1] M. Miura et al., NPG Asia Materials 9 (2017) e447.
[2] M. Miura et al., NPG Asia Materials 14 (2022) 85.
