Microstmcture control of an oxide superconductor on interaction of pinning centers and growing crystal surface

Crystal growth condition of YBCO superconductor in polycrystalline bodies under applied stress was studied for the microstructure control to improve superconducting current properties. Behavior of crystal growth front of superconducting grains through the solid state diffusion or the existence of small amount of liquid phase was examined in various conditions of temperature and applied stress. Interfacial reaction of introduced pinning centers and growing surface of superconducting matrix grains was investigated to promote the uniform dispersion of nanoparticles in matrix for increasing Jc.