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

Crystal growth condition of YBCO superconductor in polycrystalline bodies u nder applied stress was studied for the microstructure control to improve s uperconducting current properties. Behavior of crystal growth front of supe rconducting grains through the solid state diffusion or the existence of sm all amount of liquid phase was examined in various conditions of temperatur e and applied stress. Interfacial reaction of introduced pinning centers an d growing surface of superconducting matrix grains was investigated to prom ote the uniform dispersion of nanoparticles in matrix for increasing Jc.