Y <sub> 2 </ Sub> Ba <sub> 4 </ Sub> Cuwo <sub> X </ Sub> Doping On The Microstructure And Superconducting Properties Of Single Domain Ybco Bulk

With high critical temperature Tc and the strong capability of field trapping, High-temperature YBCO superconductor can be used in strong magnetic field.The crucial point to enhance the superconducting properties is to improve the flux pinning capability of the YBCO superconductors and the second none superconduting particle doping is one of the most important methods to introduce magnetic flux pinning centers and to enhance the flux pinning force.YBCO bulk superconductors have been prepared with different addition of Y2Ba4CuWOx by TSMTG to study the effect of the YW2411dopant on the pinning capability. It was found that, the top surface morphology, levitation force and microstructure of the samples were different at different addition amount of Y2Ba4CuWOx. The addition of CeO2is usually used in fact as a method of refinning the Y211size,YBCO bulk superconductors have also been prepared with different addition of CeO2by TSMTG to study the effect of the CeO2dopant through the SEM.we also found the YBCO bulk superconductors doped with Y2O3give a fine morphology,while.the addition of Y2O3indicates a higher resistance to pushing/trapping effects and yields a more homogeneous distribution of Y211particles.The YBCO bulk superconductors doped with Y2O3ware observed to trap a strong magnetic field and display higher levitation force. So the Y2O3is substitued for Y211which is doped in the YBCO bulk superconductors and the dopant influence in the microstructure is analysed.Firstly, various powders can be prepared which were needed in the TSMTG. It was found that pure powders include YBa2Cu3O7-x, Y2BaCuO5, Yb1.8Ba2.4Cu3.4Ox could be synthesized at920℃through XRD analysis. Secondly, we synthesized the single phase YW2411at1020℃. All the powders have to be calcined for three times and each sintering time is24hours.Finally, we studied the following respects of the YBCO bulk superconductors with different addition of Y2Ba4CuWOx:YBCO bulks with a single domain up to the whole size of the sample can be fabricated when Y-W2411addition x<14wt%. The levitation force of the sample increased at start and then decreased with the increase of the Y-W2411addition. The largest value can be obtained when x=2wt%, because there is a reasonable ration among the superconducting phase, Y211and YW2411phases. It is found that namometer YW2411particles (Φ100nm-200nm) uniformly scattered in Y123matrix. The levitation force decreased with the further increase of YW2411addition because of the reduced superconducting volume in the samples.YBCO bulk superconductors have also been prepared with different addition of Y2O3to study the effect of the Y2O3dopant on the top surface morphology and the microstructure through SEM.we find the size and distribution of Y211is obviously different from Y211dopant.