The enhancement of the in-field critical current density (Jc) has been one of the most important topics for magnet applications of superconductors. The addition of artificial flux pinning centers is an effective way to increase the in-field Jc and reduce the flux creep rate (S) for most superconducting materials [1-3]. Moreover, it is reported that S is almost proportional to Gi1/2, where Gi is the Ginzburg number, in REBCO and BaFe2(As1-xPx)2 (Ba122) films . However, the region between REBCO (Gi1/2~0.1) and Ba122 (Gi1/2~0.02) has not yet been investigated. To clarify the relationship between S and Gi1/2 in this unstudied region, La2-xBaxCuO4 (LBCO) is an interesting superconducting material because it has a maximal critical temperature (Tc) up to 30 K near optimal doping and a different anisotropy than REBCO and iron pnictide superconductors.
In this work, to investigate the superconducting properties of LBCO films, we fabricated LBCO films with x=0.13, 0.14, 0.15, 0.165 and 0.18 on LaAlO3 substrates using the Trifluoroacetate Metal Organic Deposition (TFA-MOD) method. The LBCO films with optimized fabrication conditions have high crystallinity and grow epitaxially on the LaAlO3 substrates. The x=0.15 film shows a Tconset~24 K and it is the highest of all the Ba content films studied. To investigate the coherence length (xab) and mass anisotropy (gH) for the LBCO films with different Ba content, we measured the r-T properties, where r is the resistivity, for various T, m0H and field angles. The calculated xab and gH are dependent on the Ba content of the LBCO films. Detailed microstructural and in-field superconducting properties for the LBCO films with different Ba content will be presented.
This work was supported by JST-FOREST (Grant Number JPMJFR202G). A part of this work at Seikei University was supported by JSPS KAKENHI (20H02184).
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 M. Miura et. al., NPG Asia Materials (accepted on Sep. 6th, 2022)