DC sputtering YBCO strip
|School||University of Electronic Science and Technology|
|Course||Materials Physics and Chemistry|
|Keywords||YBCO HTS tapes DC sputtering Planar target Multi-layer structure|
Relative to the first generation of Bi-based high temperature superconducting tapes , the second generation of the yttrium - based superconducting tapes with low AC loss , cost-effective , and has broad application prospects in the industry in the strong magnetic field download streaming ability , the HTS tapes development direction. This thesis is based on the DC sputtering DC sputtering method is simple, easy to control and process repeatability transition layer CeO2/YSZ/CeO2 (CYC) in the preparation of the nickel- tungsten alloy (Ni-5at.% W) baseband carry out the preparation of YBCO coated conductor research . The main contents are as follows : 1 . Traditional the rewinding target sputtering rate slow , the paper plane sputtering film deposition rate . YBCO coated conductors were prepared under different conditions of the low sputtering gas pressure and a high sputtering pressure , and the substrate with the target coaxial and substrate rotation found by two methods to improve the sputtering pressure and rotating the substrate binding can elimination plane the target anion anti sputtering effect . 2 . Planar target DC sputtering prepare YBCO coated conductor substrate temperature and sputtering atmosphere of the film structure , surface morphology and performance , the optimum conditions for the heating temperature of 650 ° C , total pressure 75Pa , an oxygen -argon ratio of 1:2. The film prepared in this condition is a single orientation of the c-axis , and the surface inside and outside the half-height width of 5.2 ° and 3.5 ° , respectively , the Jc of 0.75 mA / cm2 3 . ??Order to achieve the continuous preparation of the strip , the paper is prepared in the winding YBCO coated conductor to conduct a preliminary study . Can be improved by increasing the film thickness of the current-carrying capacity, but the increase in the thickness will lead to lower the critical current density of the YBCO film , using the method of the multilayer film can be optimized thin film structure and properties . Was found that in the YBCO film is more than a certain thickness , the critical current density of the film with the increase in the thickness decreased . By comparing the experimental results , we verified the multilayer film preparation method enables the structure of the film surface and optimize the performance of 4 layers of YBCO film surface roughness of less than 10nm, Jc of 0.13 MA / cm2 , this the method of process conditions to be further optimized .