Strong pinning in thick YBa2Cu3O7 layers mediated by catalysis of a new long-period metastable cuprate phase

Abstract

Catalysts are widely utilized to promote reactions in liquid and gaseous phases but are rarely encountered in solid state synthesis. Here we use catalytically active ͑001͒ ceria buffers to modify the structure of the epitaxial high temperature superconductor YBa 2 Cu 3 O 7 . The modification is achieved by catalytically-assisted synthesis of a previously unknown metastable phase. The new phase, a long-period ͑3.5 nm͒ perovskite, intercalates into the YBa 2 Cu 3 O 7 matrix without negatively affecting the critical temperature of the film. Analysis of electron microscopy and synchrotron x-ray diffraction data allow identification of the phase as a long-period YBa 2 Cu 3 O 7 derivative formed through short-range cation displacement. The 0.8 m thick films exhibit strong enhancement of the critical current density, reaching a maximum of 4.2 MA/ cm 2 at 77 K. The result emphasizes the critical role of catalysis for synthesis of novel complex materials.

Significant improvement of the critical current of MOD-derived YBa2Cu3O7-δ -coated conductors by post-annealing treatment

“…7,8) In addition, the formation of Y124-type SFs strictly depends on the oxygen atmosphere, especially at high temperatures. [9][10][11][12] The relationship between Y124-type SFs and the flux pinning effect has also been studied, showing a pinning enhancement in the ab direction. However, the relationship between Y124-type SFs and I c (77 K, self-field) has never been studied.…”

“…The peak broadening is known to be related to Y124-type SFs, which could be introduced by annealing treatments. 11,12,[15][16][17] The broadening degree is used to quantify the density of Y124type SFs, 11,15) indicating that YBCO tapes with larger broadening (00l) peaks have a higher density of Y124-type SFs. As shown in Fig.…”

Enhancement of Critical Current Density of Yttrium Barium Copper Oxide Thin Films by Introducing Nano dimensional Cerium Oxide Defects

“…(Lee, Kim, Park & Park, 1996), agreed that addition of CeO 2 into YBCO will increase the critical current density to an extent at 77K, they reported 2x 10 4 A/cm 2 an increased by lowering the measuring temperature. (Solovyov, Bagarinao, Li, Si, Win, Zhou, Wiesmann & Qing, 2010), used active (001) Ceria (CeO 2 ) buffer to modify the structure of the epitaxial high temperature superconductor YBCO which resulted with 0.8 m thick film exhibiting strong enhancement of the critical current density of 4.2MA/cm 2 . (Feng et al, 2015), used CeO 2 cap layers for high temperature superconducting, were YBCO films were epitaxially deposited on the as-growth CeO 2 / YSZ (001) stack using water-free metal organic deposition (MOD) method to obtain 1.92MA/cm 2 as J c at 77K at 0.5Pa deposition pressure.…”