Over 15\u2009MA/cm2 of critical current density in 4.8\u2009\xb5m thick, Zr-doped (Gd,Y)Ba2Cu3Ox superconductor at 30\u2009K, 3T

Goran Majkic,Aixia Xu,Venkat Selvamanickam,Eduard Galstyan,Rudra Pratap

doi:10.1038/s41598-018-25499-1

Goran Majkic, Aixia Xu + Show 3 more

Open Access

https://doi.org/10.1038/s41598-018-25499-1

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Journal: Scientific Reports	Publication Date: May 3, 2018
Citations: 40	License type: open-access

Affiliation: Manufacturing Institute, University of Houston

Abstract

An Advanced MOCVD (A-MOCVD) reactor was used to deposit 4.8 µm thick (Gd,Y)BaCuO tapes with 15 mol% Zr addition in a single pass. A record-high critical current density (Jc) of 15.11 MA/cm2 has been measured over a bridge at 30 K, 3T, corresponding to an equivalent (Ic) value of 8705 A/12 mm width. This corresponds to a lift factor in critical current of ~11 which is the highest ever reported to the best of author’s knowledge. The measured critical current densities at 3T (B||c) and 30, 40 and 50 K, respectively, are 15.11, 9.70 and 6.26 MA/cm2, corresponding to equivalent Ic values of 8705, 5586 and 3606 A/12 mm and engineering current densities (Je) of 7068, 4535 and 2928 A/mm2. The engineering current density (Je) at 40 K, 3T is 7 times higher than that of the commercial HTS tapes available with 7.5 mol% Zr addition. Such record-high performance in thick films (>1 µm) is a clear demonstration that growing thick REBCO films with high critical current density (Jc) is possible, contrary to the usual findings of strong Jc degradation with film thickness. This achievement was possible due to a combination of strong temperature control and uniform laminar flow achieved in the A-MOCVD system, coupled with optimization of BaZrO3 nanorod growth parameters.

Highlights

It is remarkable that a nearly 5 μm thick film has been grown in a single pass without any degradation in texture or BZO nanorod alignment, which simplifies the deposition and reduces the processing cost significantly
Record-high critical currents of 8705 A/12 mm, 5586 A/12 mm and 3606 A/12 mm have been obtained at 30 K, 40 K and 50 K respectively in a magnetic field of 3T (B||c) which are approximately two times higher than the best value reported in literature
In-field Ic measurements were performed in a 9T solenoid system over temperature and field ranges of 30 K to 50 K and 0 to 9T, respectively, and over the angular range of −105° to 35° relative to the tape normal direction