[PCP2] Physics and Chemistry2

[PCP2-12] The effect of Sr content on superconducting properties of TFA-MOD (La_2-xSr_x)CuO₄ films

*Takumi Kuwada¹, Ryusei Kaji¹, Mahiro Kaiya¹, Yuki Ogimoto¹, Masashi Miura^1,2 (1. Seikei University (Japan), 2. JST-FOREST (Japan))

Keywords:

critical current density,TFA-MOD,(La2-xSrx)CuO4 ((La,Sr)214),critical temperature

For widespread superconducting applications, the REBa₂Cu₃O_y(REBCO) superconductor has been actively investigated, because it has a relatively high critical temperature (T_c) and critical current density (J_c) among various superconducting materials. Toward further increase of the J_c property, we recently found that a combination of improving the thermodynamic parameters and increasing the density of flux pinning centers is an effective way for the superconductors (Y_0.77Gd_0.23)Ba₂Cu₃O_y ((Y,Gd)123), FeSe_1-xTe_x (Fe11), BaFe₂(As_1-xP_x)₂ (Ba122) and SmFeAsO_1-xH_x (Sm1111) [1-3]. Based on those results, we consider that the key parameters for high J_c are the nanoparticle density (N_p), T_c, coherence length (ξ_ab) and penetration depth (λ_ab). To clarify the relationship between the key parameters and J_c for various superconducting materials, we now focused on (La_2-xSr_x)CuO₄ ((La,Sr)214) films.In this work, to study the effect of Sr content on the superconducting properties, we fabricated (La,Sr)214 films with various Sr concentrations on LaAlO₃ substrates using the Trifluoroacetate Metal Organic Deposition (TFA-MOD) method. All of the epitaxially grown (La,Sr)214 films show high crystallinity. In this work, the highest J_c at 4.2 K was obtained for films with x = 0.2 despite a slightly lower T_c compared to that of optimally Sr doped films. Detailed superconducting properties for (La,Sr)214 with different Sr contents will be presented.