By Dc Sputtering Ybco Strip Study

YBa2Cu3O7-δ(YBCO) superconducting tapes have promising electronic and electric applications ,because of its the high critical current density (Jc) in external magnetic fields, lower ac loses and processing costs. YBCO HTS tapes (also called coated conductors) attract the attention of the researchers worldwide. In this thesis, YBCO coated conductors were deposited on Y2O3/YSZ/CeO2(YYC) buffered Ni-5at.%W substrate with sputtering because it is easy to control and high reliability. The main content of this thesis including:1. According to the relationship between temperature and c-axis textured orientation of Y2O3 seed layer, the optimal temperature was obtained. And then we studied the optimal water partial pressure according to the hysteresis characteristic of the reactive sputtering. The Y2O3 seed layer film with pure c-axis orientation was deposited under the condition of the temperature being 720℃, sputtering current being 0.2A and water partial pressure being0.016Pa.The full width at half maximum(FWHM) of in-plane and out-of-plane scan are 3.9°and 4.9°.2. The surface roughness of the Y2O3/YSZ/CeO2 (YYC) buffered layer has a great influence to the quality of the YBCO coated conductors. The YYC buffer layers which were prepared by reactive sputtering and the RF sputtering were pure c-axis orientation , and the FWHM of in-plane and out-of-plane scan were similar, but the root mean square (RMS) roughness of the YYC that prepared by reactive sputtering is significantly greater than that of YYC prepared by RF sputtered, As a result, the critical current density of YBCO thin film that deposited on the former buffer layer was 1.2 MA/cm2, but that of YBCO thin film on the latter reached 2.8 MA/cm2.3.The fabrication of YBCO by reel-to-reel technology has been studied, the optimal temperature is 780℃. Because the negative ions bombardment effect of the plane target was obvious, we changed the speed of the reel-to-reel to compensate the component deviation. The critical current density of YBCO thin film reached 0.6 MA/cm2 under the condition that the distance between target and substrate was 20 mm, the total gas pressure was 70Pa and the speed of the reel-to-reel was 0.55m/h. 4.The performance of the YBCO coated conductors in magnetic field had been studied,we applied magnetic field of 0-2T that is perpendicular to the substrate surface at the 65K and 77K, found that the YBCO films with Y2O3 particles, pinning centers have showed substantial improvement in comparison with pure YBCO films in magnetic field.