Solution-derived YBa₂Cu₃O₇nanocomposite films with a Ba₂YTaO₆secondary phase for improved superconducting properties

Abstract

We report on the spontaneous segregation of double perovskite Ba 2 YTaO 6 (BYTO) nanoparticles within YBa 2 Cu 3 O 7 (YBCO) films forming a nanocomposite with two ternary oxides by the low cost and scalable chemical solution trifluoroacetate approach. Phase orientation, nanostructural and pinning studies are carried out by 2D x-ray diffraction, advanced scanning transmission electron microscopy and transport measurements, respectively. In this complex oxide nanocomposite system (YBCO-BYTO) the majority of the nanoparticles segregated within the (00l)-oriented superconducting matrix are randomly oriented. The presence of randomly oriented nanoparticles plays a key role in the generation of localized highly strained areas within the YBCO matrix which are suggested to strongly affect the superconducting properties. The incorporation of 6-10% of BYTO resulted in a maximum pinning force, at 77 K, three times higher than that obtained for a pristine sample, while T c was maintained at 89-90 K.

Epitaxial YBa2Cu3O7−xnanocomposite thin films from colloidal solutions

“…The CSD methods excel in their low investment costs and scalability compared to vacuum techniques while the growth mechanisms are deeply modified [17][18][19][20][21][22][23][24][25][26]. In this case, complex solutions are prepared where the salts used to prepare YBCO (trifluoroacetates, TFA) are extended to a fourth element (Zr, Hf, Sn, Ta) through soluble metal-organic salts with the desired stoichiometry to achieve secondary phases such as BaZrO 3 , BaSnO 3 , BaHfO 3 , Ba 2 YTaO 6 , etc [16,[27][28][29]. This single solution precursor leads, after deposition and growth, to a spontaneous segregation of two separate oxide phases (in-situ nanocomposite approach).…”

Influence of YBa 2 HfO 5.5 – ‘derived secondary phase’ on the critical current density and flux-Pinning force of YBa 2 Cu 3 O 7−δ thick films

“…A twofold improvement in J c value by the addition of BaTiO 3 in YBCO films was reported by Jha et al [18]. Similarly, rapid enhancement in flux pinning and critical current density was observed in YBCO films by the incorporation of nanoparticles such as BaSnO 3 [9], BaHfO 3 [22] Ba 2 YTaO 6 [23], Ba 2 YNbO 6 [24,25] and Ba 2 RETaO 6 [26]. In our earlier works, we had reported the effect of addition of simple oxide, HfO 2 [27], ABO 3 type perovskite, nano BaHfO 3 [28,29] and double perovskite YBa 2 HfO 5.5 [30] tremendous improvement in flux pinning force and critical current density.…”

6. Vortex dynamics in nanofabricated chemical solution deposition high-temperature superconducting films

“…It has been demonstrated that the presence of these randomly oriented nanoparticles induces the formation of a large density of stacking faults that produce strong lattice distortions in the YBCO matrix, which act as very efficient strong isotropic pinning centers [10,30]. YBCO films with BaZrO 3 (BZO) nanoparticles, for example, have shown enhanced pinning forces (75 GN/m 2 and 600 GN/m 2 at 3 T, 65 K and 9 T, 10 K, respectively) [4], more than five times larger than standard films grown by the same process [10].…”