radio-frequency-magnetron-sputtering-gdba2cu3o7-la067sr033mno3-quasi

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.

Article	Year
Fabrication and characterization of La2Zr2O7 films on different buffer architectures for YBa2Cu3O7-δ coated conductors by RF magnetron sputtering. Nanoscale research letters\| PubMed ID: 23445764	2013
Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 - Î´ thin films fabricated by RF sputtering. Nanoscale research letters\| PubMed ID: 23816137	2013

Linfei Liu

Biography

JoVE Journal Publications

Other Publications