摘要 : High temperature superconductor YBa_2Cu_3O_(7-x) (YBCO) nanopowders were successfully prepared by a citrate pyrolysis technique. The phase formation and microstructure of the nanopowders were studied. The microstructure analysis s... 展开 High temperature superconductor YBa_2Cu_3O_(7-x) (YBCO) nanopowders were successfully prepared by a citrate pyrolysis technique. The phase formation and microstructure of the nanopowders were studied. The microstructure analysis shows that the obtained YBCO powders have very fine grains with a size around several tens of nanometers. The superfine morphology reveals that the thermal agglomeration of the particles decreases with decreasing the annealing temperature and shortening the annealing time. In addition, the complete phase formation of YBCO depends upon the annealing temperature and the annealing time as well. So far, these nanopowders have been used to fabricate the melt-textured YBCO bulk materials. 收起