Radio Frequency Magnetron Sputtering of GdBa2Cu3O7&#8722;&#948;/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 (STO) Single-crystal Substrates

Here, we demonstrate a method of coating ferromagnetic La0.67Sr0.33MnO3 (LSMO) nanoparticles on (001) SrTiO3 (STO) single-crystal substrates by radio ...

Shanghai Jiao Tong University

La2Zr2O7 (LZO) films were grown on different buffer architectures by radio frequency magnetron sputtering for the large-scale application of YBa2Cu3O7-x (YBCO)-coated conductors. The three different buffer architectures were cerium oxide (CeO2), yttria-stabilized zirconia (YSZ)/CeO2, and CeO2/YSZ/CeO2. The microstructure and surface morphology of the LZO film were studied by X-ray diffraction, optical microscopy, field emission scanning electron microscopy, and atomic force microscopy. The LZO films prepared on the CeO2, YSZ/CeO2, and CeO2/YSZ/CeO2 buffer architectures were preferentially c-axis-oriented and highly textured. The in-plane texture of LZO film on CeO2 single-buffer architecture was ∆ φ = 5.5° and the out-of-plane texture was ∆ ω = 3.4°. All the LZO films had very smooth surfaces, but LZO films grown on YSZ/CeO2 and CeO2/YSZ/CeO2 buffer architectures had cracks. The highly textured LZO film grown on CeO2-seed buffered NiW tape was suitable for the epitaxial growth of YBCO film with high currents. 

Fabrication and characterization of La2Zr2O7 films on different buffer architectures for YBa2Cu3O7-δ coated conductors by RF magnetron sputtering.

GdBa2Cu3O7 - Î´ (GdBCO) films with different thicknesses from 200 to 2,100 nm are deposited on CeO2/yttria-stabilized zirconia (YSZ)/CeO2-buffered Ni-W substrates by radio-frequency magnetron sputtering. Both the X-ray diffraction and scanning electron microscopy analyses reveal that the a-axis grains appear at the upper layers of the films when the thickness reaches to 1,030 nm. The X-ray photoelectron spectroscopy measurement implies that the oxygen content is insufficient in upper layers beyond 1,030 nm for a thicker film. The Williamson-Hall method is used to observe the variation of film stress with increasing thickness of our films. It is found that the highest residual stresses exist in the thinnest film, while the lowest residual stresses exist in the 1,030-nm-thick film. With further increasing film thickness, the film residual stresses increase again. However, the critical current (Ic) of the GdBCO film first shows a nearly linear increase and then shows a more slowly enhancing to a final stagnation as film thickness increases from 200 to 1,030 nm and then to 2,100 nm. It is concluded that the roughness and stress are not the main reasons which cause the slow or no increase in Ic. Also, the thickness dependency of GdBa2Cu3O7 - Î´ films on the Ic is attributed to three main factors: a-axis grains, gaps between a-axis grains, and oxygen deficiency for the upper layers of a thick film.

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 - Î´ thin films fabricated by RF sputtering.

GdBa2Cu3O7 - films &delta; (GdBCO) avec diff&eacute;rentes &eacute;paisseurs de 200 &agrave; 2 100 nm sont d&eacute;pos&eacute;s sur zirconium CeO2/yttrium-stabilis&eacute; (YSZ) / substrats CeO2 tampon Ni-W par magn&eacute;tron radiofr&eacute;quence bredouillement. La diffraction des rayons x et les analyses de microscopie &eacute;lectronique &agrave; balayage r&eacute;v&egrave;lent que les grains a axes apparaissent dans les couches sup&eacute;rieures des films lorsque l&#39;&eacute;paisseur atteint &agrave; 1 030 nm. La mesure de spectroscopie photo&eacute;lectronique des rayons x indique que la teneur en oxyg&egrave;ne est insuffisante dans les couches sup&eacute;rieures au-del&agrave; de 1 030 nm pour un film plus &eacute;pais. La m&eacute;thode de Williamson-Hall sert &agrave; observer la variation de tension de film avec l&#39;augmentation de l&#39;&eacute;paisseur de nos films. Il se trouve que les contraintes r&eacute;siduelles plus hauts existent dans le film plus mince, tandis que les plus faibles contraintes r&eacute;siduelles existent dans le film de 1 030-nm d&#39;&eacute;paisseur. Avec augmentant encore l&#39;&eacute;paisseur du film, les contraintes r&eacute;siduelles film augmentent de nouveau. Cependant, le courant critique (Ic) de la GdBCO film montre d&#39;abord une augmentation presque lin&eacute;aire, puis affiche une plus lente am&eacute;lioration &agrave; une stagnation d&eacute;finitive comme &eacute;paisseur de film augmente de 200 &agrave; 1 030 nm, puis &agrave; 2 100 nm. Il est conclu que la rugosit&eacute; et le stress ne sont pas les principales raisons qui causent la lente ou aucune augmentation de l&#39;Ic. En outre, la d&eacute;pendance de l&#39;&eacute;paisseur de la GdBa2Cu3O7 - films &delta; sur l&#39;Ic est attribu&eacute;e &agrave; trois facteurs principaux : un axe des c&eacute;r&eacute;ales, les &eacute;carts entre les grains d&#39;un axe et manque d&#39;oxyg&egrave;ne pour les couches sup&eacute;rieures d&#39;un film &eacute;pais.

D&eacute;pendances de microstructure et stress sur l&#39;&eacute;paisseur du GdBa2Cu3O7 - &delta; minces fabriqu&eacute; par pulv&eacute;risation RF.

Bisphenol A (BPA) is a well-known endocrine disrupting chemical (EDC), ubiquitous in the aquatic environment, which poses an ecotoxicological risk to the health of aquatic organisms. However, the immunotoxic effects of its long-term exposure on fish have received limited attention. We examined a number of typical immune-related parameters and oxidative stress indices in the liver and blood serum of the red common carp (Cyprinus carpio), following a 30-day exposure to five different concentrations of BPA (0.1, 1, 10, 100, and 1000μg/L). A significant increase in the hepato somatic index was observed in fish upon exposure to 1000µg/L BPA, which correlated strongly with the accumulated BPA concentrations in fish bile. Induced oxidative stress was also apparent in the exposed fish liver, based on the enhanced levels of lipid peroxidation and inhibited activities of catalase, superoxide dismutase, and glutathione peroxidase. Serum lysozyme and C-reaction protein levels increased at low concentrations of exposure; however, they were significantly suppressed upon exposure to high concentrations. A significant increase was observed in the levels of immunoglobulin M, complement component 3, and alkaline phosphatase, in both fish liver and serum at low doses of 0.1 and 1μg/L. This suggests that long-term exposure to environmentally relevant concentrations of BPA (even as low as 0.1μg/L) could significantly disturb the immune response of fish. Moreover, RXRα expression in the liver was significantly altered upon BPA exposure and the trend underlying this change correlated closely with those of the most immune-related parameters, implying the involvement of the PPARγ/RXRα signaling pathway in regulating the immune response of fish upon long-term BPA exposure. In short, our results demonstrate the susceptibility of fish immune system to long-term BPA exposure. Therefore, the immunotoxicity of EDCs in aquatic organisms should not have been underestimated. 

Yijie Li

Key Laboratory of Artificial Structure and Quantum Control,
Ministry of Education,
Department of Physics,
Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics

Shanghai Jiao Tong University

Radio Frequency Magnetron Sputtering of GdBa₂Cu₃O₇₋_δ/ La_0.67Sr_0.33MnO₃ Quasi-bilayer Films on SrTiO₃ (STO) Single-crystal Substrates

Yijie Li

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Key Laboratory of Artificial Structure and Quantum Control,Ministry of Education,Department of Physics,Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics

Shanghai Jiao Tong University

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7−δ/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 (STO) Single-crystal Substrates

Key Laboratory of Artificial Structure and Quantum Control,
Ministry of Education,
Department of Physics,
Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics

Radio Frequency Magnetron Sputtering of GdBa₂Cu₃O₇₋_δ/ La_0.67Sr_0.33MnO₃ Quasi-bilayer Films on SrTiO₃ (STO) Single-crystal Substrates