Abstract
釔鋇銅氧超導體在超導態之電性可分成兩部份.在高溫時,超導性由準二維轉變成三維.在低溫時,磁通液體會凝固成磁通固體We have carried out a series of detailed resistive measurementsnear the superconducting transition region of the YBCO system.The data show that a distinct resistive "kink" at Rs/Rn=20% infield along the c-axis exists in all samples studied andpersists to the highest field applied. This resistive "kink" isdue to the dimensional crossover of superconductivity fromquasi-2D to 3D. An additional resistive "knee" at Rk/Rn=10%in arange of external magnetic fields. This resistive "knee" isattributed to the vortex solid (vortex lattice or vortex glass)to vortex liquid transition.